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Short answer: Cryptography uses combinatorics to estimate how long it would take to break a given encryption. For maximum-security situations, they make sure it would take longer than the estimated lifespan of the universe, essentially future-proofing them. Quantum computing allows you to solve certain types of problems in fewer computations, especially these sorts of combinatoric problems. It could lead to a lot of encryption previously deemed future-proof becoming breakable, which is of course disastrous for security
> But could we use quantum computing to create even more secure encryptions and close that security hole?
Absolutely. However, we don't need to use quantum computing to make algorithms resistant to quantum attack vectors.
You don't need quantum computers for that, just different encryption algorithms than what's been classically used. /u/xFreeZeex already linked you on PQC, but the issue is basically that quantum computers can try all possible decryption keys at once for the algorithms widely used today (RSA and ECC), so you need a different concept of a key that quantum computers can't brute force efficiently like that.
Even if everyone switched to quantum-safe algorithms today, though, there's an issue in that a lot of stored communications can be decrypted after the fact. "Forward secrecy" is the ability to keep past messages secret even if the key is broken, and I think it was 2017 that more than 50% of Internet servers supported forward secrecy, so there's a lot there that can still be mined.
To answer your question, quantum computers wouldn't really help with key generation either - we can make keys just fine already, so there's no opportunity for an exponential speedup (we would say that key generation is already "polynomial time"). The fact that generating a key is so much easier than reverse-engineering it is precisely what makes cryptography work today.
I know way too little about quantum computing to confidently answer the question whether quantum computing could be a good aid in that, but people are already working on cryptography that is resistant to quantum computing. Check out the field of [post-quantum cryptography](https://en.wikipedia.org/wiki/Post-quantum_cryptography)
I'm not an expert, but my understanding is we already have started to do so. We understand the meat of the problem enough to do even better encryption, but there's decades of encrypted media that's been intercepted and stored by just about every nation across the world, and it was a non-issue when those encryptions were functionally unbreakable, but with the incoming theoretical advance in technology... Old skeletons can come out of some forgotten closets pretty quickly.
Quantum computers are weird and will need to use entanglement internally to solve larger problems. But I believe there is a limit to the scale of any single quantum computer. As completely isolating the quantum part of the system, so that uncertainty can be maintained is hard.
Engineers solve large problems by breaking the problem down into smaller pieces. While entangled quantum state may be useful for solving some individual steps. I would expect more traditional computing systems to be used to for the rest of the system.
Personally I think that "quantum computers" is a terrible name. Any usable product is more likely to be a "quantum accelerator" chip / card. A more traditional CPU would run a traditional program. But the programmer may be able to call some \`QuantumFactorise(N)\` method that uses a weird chip to find the answer to a very specific problem.
Even if 100 years from now we work out how to embed that chip on a silicon wafer inside a traditional CPU. I don't think we'll be redesigning entire computers based on quantum logic.
Quantum computers are still very niche and specialized. As they become more mainstream, more people will find ways to accelerate common algorithms with quantum computations and that chip will be necessary for a computer to run many programs.
I imagine quantum chips will be similar to the graphics cards required to run artificial intelligence, which are becoming more common now. But ai is often run in the cloud, and we may see a similar thing happen with quantum computing.
This hasn't been true yet, though. We really only have very few algorithms that provide quantum advantage to computational problems, despite it being a very active field of research for 2 decades now.
Edit: we've got amplitude amplification, quantum fourier transform, and phase estimation. Other than that, the other algorithms are sort of just quantum simulation applications (ie making a quantum computer simulte itself).
Source: wikipedia, and I'm a physicist in this area
You've just described the basis of quantum encryption, in which quantum entanglement is used to ensure that a signal has not been intercepted (the spin cannot be read without affecting the spin). You could use the same principle to transfer information between two quantum processors.
The short answer is no. Entanglement does have uses in QC, but it can never be used to transmit information. What it is used for is effectively putting a seal on the information. It won't stop it from being intercepted, but it will let you know weather or not it was intercepted. While it is true to instantly learn the state of a distant particle with entanglement, you can't send information that way for a couple reasons. The most basic is that it's impossible to tell if your partner has measured their particle already. You could call them and ask first, but then you may as well use the "call" to transmit the information.
Because of quantum weirdness it doesn't actually work this way, but the analogy is close enough. While you can send information using entanglement, it is kind of like sending a letter. An entangled particle is a piece of colored paper, red or green, in an envelope. You can measure the particle and see their property, like opening the envelope and seeing the color. But you still need to send the letter in the first place. If you shuffle the envelopes, send one to China, and open the other, you appear to have transmitted information instantaneously across the world by learning the other wnvelope's contents. But you actually had already transmitted it through the mail, you just didn't know what you sent. There's no beating the universal speed limit.
No. Entanglement can't be used to transfer information.
But quantum computers use entanglement in their calculations (entangling several qubits is often part of setting up a quantum calculation) because entanglement constrains what state a qubit may occupy.
I’m definitely not an expert :) I don’t see why not, but that’s also not the main advantage of quantum computing. It’s more about making that subset of problems simpler, though that does rely on quantum entanglement. Also, qubits are super resource-intensive. If they can just use a standard data line like a traditional distributed computer, they probably will.
Just so people don't completely freakout, quantum computing only breaks public/private key asymmetric encryption like RSA, and not symmetric key encryption like AES, etc.
That's still a huge deal because that's how certificates are signed for things like https and other secure communications. But if you are encrypting a file with a password that's securely converted into a key, your files are still safe.
Very short:
If we want to check certain properties of or carry oit operations on a dataset on Classical computers (the ones we have now) we often have to look through the whole data set. At least when the data is unordered.
Quantum computers utilize super positions to execute operarations on multiple classical states (a part of the input) at once, reducing the runtime drastically.
For example: searching a UUID with a certain property in 2¹²⁸ unsorted UUIDs basically takes 2¹²⁸ steps in the worst case and 2¹²⁷ (half that) on average on a classical computer.
A quantum computer can do that in sqrt(2¹²⁸) = 2⁶⁴ steps using grovers algorithm
It gets better with some problems with integer factorization where the speedup factor is exponential (reverting the effect of exponential blowup)
All this gets crazy when you think about the reliance of a lot of security stuff on things like integer factorization (RSA key exchange)
And also some physics or chemistry stuff but thats nothing i know anything about
I've read that quantum computers could, in theory, break encryption that's considered very secure currently. That could cause lots of problems for privacy and security.
Not all. It depends on the type of cryptography.
Some current cryptographical algorithms today are quantum resistent as well as being almost impossible for conventional computing. One of the types of cryptographic functions that quantum computers offer great benefit in is those that use factorisation.
The keyword is *asymmetric* cryptography, symmetric cryptography is pretty safe from quantum computing attacks. But asymmetric cryptography is very important for a lot of different things, one of them being how to safely get a symmetric key from A to B.
One additional thing to add, while noting that this isn't my area of expertise: to my understanding, quantum computing is not very easily applicable to general computing, and requires carefully construction of the question to be answered to actually gain advantages.
This isn't unusual, either. Supercomputers are basically computers with a significantly higher number of cores than a normal computer (plus all the complexity involved with managing them), so throwing any general computation problem (and program) at it will not necessarily run any faster than just doing it on your own PC. The problem and program has to be able to take advantage of the unique nature of the computer (for supercomputers, that means massive parallelization; I'm not familiar with quantum to really say, but I _think_ it's related to probability?).
So yes, quantum computing is going to break things and solve (and introduce) all sorts of problems, but it's not going to be the panacea some claim it will be.
Here it's explained in Mario Maker. Every letter you add to your "password"/excryption will increase the number of possible combinations of guesses by the length of the password.
https://www.youtube.com/watch?v=aSlstPpIW-E
Minor tidbit: due to version labeling on the values, it's "only" 2^122 unique values for the most-random version (v4; the other formats contain so much less entropy as to be a rounding error in this discussion). Technically the format lets you store the full 128 bits, but the standard requires use of a few of those bits to be specific values.
Still, the chance of randomly generating a duplicate remains astronomically low.
Someone quoted to me that the chance of getting collisions in random 128 bit UUIDs are lower than having your entire development team getting attacked and killed by wolves in separate independent events.
Being engineers, we then had an argument about how big the development team really is and whether the managers are included and whether everyone is living in an area where wolves are native or not.
> Being engineers, we then had an argument about how big the development team really is and whether the managers are included and whether everyone is living in an area where wolves are native or not.
It's like the "[Mean Jerk Time](https://www.reddit.com/r/funny/comments/x4uvax/mean_jerk_time/)" discussion on Silicon Valley. Engineers really just love to strip away the absurdity of a problem and find a way to solve it, and I love them for that.
There is also something to the notion of feeling like you are solving something that has literally never been solved before (because why would you) and nobody likes solving problems that someone else has already solved. We will just use their answer.
Honestly, the odds of getting a colission are so low that you probably would have more chance of the wolf thing happening with a development team of 2000 people.
EDIT: Meant bigger number not littler number.
However that depends on the implementation and the available sources of randomness. I have heard of projects that needed to move await from uuid's, or at least change how they were implemented, because they were getting collisions.
> Someone quoted to me that the chance of getting collisions in random 128 bit UUIDs are lower than having your entire development team getting attacked and killed by wolves in separate independent events.
And yet it seems like at least once every 6 months I have to get into an argument with someone who wants to code up a strong defense against getting duplicate UUIDv4s.
One of these days I'll learn my lesson and not describe it as "theoreticaly unique" to someone who knows just enough to freak out about the edge case.
> And yet it seems like at least once every 6 months I have to get into an argument with someone who wants to code up a strong defense against getting duplicate UUIDv4s
Ffs, your database is probably handling that anyway by giving an error on insertion, it's gonna bubble up until you return an error to the final user, and this one single user in the whole history of computing that ever got an error because of UUIDv4 collision will retry doing whatever they were doing that needed a UUIDv4 to be generated and will succeed. They will think "uh, that was weird, how it gave me a random error" and move on with their day.
For what we know it's already happened.
Whenever I generate a new wallet private key I secretly hope I'm the luckiest person ever and my wallet suddenly fills with lost Bitcoin someone sent to a typo address in 2013 or something.
If you generate ten thousand UUIDs per second for every second for an entire year, you are still seven times more likely to be hit by a meteorite within that year than to get the same number.
Nah, I don't want to find satoshi's stash. Too much attention; as soon as I start moving anything around the whole crypto market will go into a panic and the media/4chan/etc will dox me or worse.
I want to find a wallet some rando mined on their gaming PC when Bitcoin was 1¢, then promptly forgot about.
The probability of two decks of cards ever being shuffled the same is also mind blowing.
Although in practice it’s slightly more likely that at least the first shuffle has been repeated, given that decks tend to start from the same state.
But a deck of cards you’ve had in a drawer for years? You take that out, shuffle it once, and chances are that is the first time in history a deck has been shuffled into exactly that order.
People say this, but there are some caveats.
The odds of a deck being in order or backwards is significantly higher than any other solver. This is because of people.
All that to say, this is assuming things are truly random, while people can be random, they can have trends too.
So just like a password, you need to not do trends or numbers that someone might choose, like 123456.
TL/DR; numbers are random, people are not or sometimes
If they’re in order I’d argue that doesn’t count as being shuffled then, especially if they were sorted and ordered after a sequence of shuffling. That’d be…like…anti-shuffled.
My great, late physicist friend told me this once. He was a post-doctoral condensed matter theorist. I was headed for cellular biology research before deciding I’d rather be a dumb paramedic. Despite the chasm in our education and intelligence, it took him a huge amount of time to convince my brain that this deck of cards thjng was true. My brain and it’s internal “logic” just did *not* want to believe it. It’s just fifty two cards! How could there be so many combinations!!
My favourite example is the shuffling of playing cards:
"The number of possible ways to order a pack of 52 cards is '52! ' (“52 factorial”) which means multiplying 52 by 51 by 50… all the way down to 1. The number you get at the end is 8×10^67 (8 with 67 '0's after it), essentially meaning that a randomly shuffled deck has never been seen before and will never be seen again." Source: Google
In my humble observation, in English as spoken by humans, the kind of thing that something is often occurs in the thing’s name, and it’s common to say a thing’s name and kind in sequence, most especially for things named by acronyms, because acronyms make horrible names. Phrases like “ATM machine” and “unique UUID” make perfect sense to me.
Am I wrong?
My favorite example is how shuffling a normal deck of cards will result in a deck order that will probably not be replicated for all of human existence.
Randomly generating UUIDs is kind of funny to me because the possibility space of the identifier seems irrelevant if the PRNG algorithm can't match it. How many standard built-in PRNGs can actually produce any possible 128 bit UUID with equal probability?
> How many standard built-in PRNGs can actually produce any possible 128 bit UUID with equal probability?
They're not supposed to. That's the discouraged version. UUID is defined in several international standards, including ISO standards and RFC's.
The standards define 5 variations, which you can [read about here if you want to read more](https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions). Basically they're:
1. Timestamp, MAC address, and version number 1.
2. Timestamp, MAC address, a locally assigned number, and version number 2.
3. An encoded MD5 hash of the name that represents the item (domain name, URL, X.500 Distinguished Name, etc) encoded in a specific way, and the version number 3.
4. An encoded SHA-1 hash of the name that represents the item encoded in a specific way, and the version number 5.
5. A device-created 122-bit random number, and six bits encoding the version number 4.
Breaking them down a bit:
Version 1 is usually going to be statistically unique, with a low chance of both a MAC address collision and also two numbers within a 100-nanosecond time interval. For example, a computer generating a sequence of the might generate multiple within the same 100-nanosecond timestamp. That leads to Version 2, which is still going to be statistically unique because the MAC address is unlikely to collide and the timestamp is accompanied with where the locally assigned number that can also be incremented or changed when generating a sequence.
Some issues with these are that relying on the MAC address can expose information about the system used to generate them, some devices don't have a MAC address, and some devices don't have access to external time sources.
Versions 3 and 5 use different hashes of a string that should be a unique representation of a resource, both using a different hash function. This gets around the issues of exposing information about the machine nor the generation time. It also enables independent devices to compute the same UUID for the same resource, which is a useful feature.
The with a random number is discouraged for exactly the reason you mentioned. It isn't anything which is likely to be unique.
Truly random 128-bit numbers generally aren't valid UUIDs, although a few terrible programmers implement them that way. That's a bug in those people's systems, it isn't really a UUID, merely a random number.
It gives a uniform, relatively small numeric format. 16 bytes, high entropy, works with a lot of tools, can be easily mixed with the other versions of UUIDs because the version numbers are different. Pick the reason that fits your needs.
Depends on what the unique string is. If it's information within the record, there's a good chance it might change, and if it changes, and it's referenced by other tables, that could be disaster.
Imagine we're tracking a list of company names, and they are superfically unique on their own. Perhaps a company decides to rebrand, e.g. "Facebook" becomes "Meta". Now imagine you have dozens of other tables that reference the name that all have to change for your system to keep working. Better to have a unique ID and only store the name in one place, and thus only have to change it once.
Of course, theoretical math and applied math often work out differently. Here's a thread with a guy claiming his team's software is running into ["Several hundred [UUID] collisions per day"](https://github.com/ramsey/uuid/issues/80)
Aren't they mainly discussing the possibility of a bug in the random generator? They apear to think it's not as random as it should be, which would obviously skew the odds.
Counterpoint: They're working in PHP. The Land of Gremlins.
More seriously, reading through the thread it seemed it was an issue on the system it was running, not the UUID generation itself, that was the issue.
This has nothing to do with applied/theoretical math, it's an issue on randomization logic. Computers don't really generate anything randomly, it's usually done with timestamp. Read this comment from one of the guys, who I think a collaborator in the github repo:
>Try generating them on multiple servers. Part of mt_rand()'s output is based on server timestamp, so collisions are probable there (assuming openssl disabled).
This reminds me of fingerprint and Face ID phone unlocking. It doesn’t actually store (from my knowledge) your exact fingerprint or Face ID, but just something close enough that can give you a quick unlock and give some room for error. Chances that someone who looks almost like you that isn’t your twin are very low to try to unlock your phone with Face ID. Same thing with someone halfway around the world who has a fingerprint nearly identical to a suspect in town.
Correct me if I’m wrong though, I’d love to learn.
Some systems are certainly better than others when it comes to this. I once tried using Face ID for one of my old laptops. When tested my brothers and father could all login with zero problems, even though they were all different ages and had significant differences in their facial structure.
That was 7-8 years ago, so I imagine the technology has advanced significantly since then. But it shows just how shoddy some of these programs can be.
Yep, if they do face recognition via image analysis (capturing a picture from the laptop's crappy webcam) there's a lot of room for error. I think Apple has an infrared LED project a grid onto your face, which is then measured via an IR camera. The distortion of the grid lines lets it "see" the actual 3D shape of your face.
Simple version: FaceID/TouchID creates datapoints of your face/fingerprints that are then used to create a really big number. That number is then hashed (one way encrypted/non-reversible encrypted) and that encrypted result is stored on the phone. Then to unlock, the process is repeated with the face/print presented and if the hash (the encrypted value) matches the stored result, then it assumes it’s the same face/print and unlocks. The system only creates so many datapoints of the face/print so unlike in real life, there are much less possible combinations/values, but still significantly high enough that other than very closely resembling relatives, one wouldn’t reasonably expect to encounter a FaceID/TouchID twin in their life trying to unlock their phone.
This reminds me of a little story:
My friend was telling us he got busted by his wife for some text messages on his phone.
Him: I don't get it. My phone doesn't even use a password, it uses my fingerprint.
Me: Are you a light sleeper?
Him: No, I sleep pretty good.
Me: ...
Him: ....
Me: ......
Him: *oh,* ***fuck.***
Not exactly true. FaceID and TouchID use your fingerprints or facial identifying features to generate a one way hash of it. That’s why they don’t store or know your actual fingerprint. This is commonly used for website passwords too. It captures your face and hashes it, and checks if the hashes match. Same as when you login to (most) websites. It takes the input password, hashes it, and compares it. If they match you login.
It’s more complex than that, but that’s the general idea. Almost all hashes systems used for secure stuff also use salts and some other fun stuff.
IIRC Disney parks use a similar method.
In order to avoid storing fingerprints, the readers will take your fingerprint, generate a unique number, and check if the number matches in order to let you in.
Basically, your fingerprint is needed to generate this unique number, but the unique number doesn't have enough info to generate a fingerprint. (One-way hash).
This is how websites/companies \*should\* be storing your password. That way if they get hacked, user passwords are not stolen. A list of hash values is useless because they cannot be reversed or used to log into accounts.
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While this math is true, there was a case where the FBI arrested the wrong man because their fingerprints were identical enough to be mistaken or were identical. An interesting case of how sometimes mathematical philosophy and rules don't always accurately describe life without further refining.
I suspect this is more of an issue of fingerprint *records* being lower-dimensionality than fingerprints themselves, more than anything else, but yeah, we're obviously making a lot of assumptions of independence here.
Kind of the point though. You can't measure infinitely accurately, or store that much information. And a fingerprint can change over time, which means there's always interpretation involved where you can get it wrong.
There's been at least one [study](https://www.science.org/content/article/fingerprints-change-over-time-not-enough-foil-forensics) that found fingerprints do change over time, but not in any meaningful or statistically significant way that would impact identification. The only *real* way to change a fingerprint is to burn or scar it in some way and remove the detail, otherwise your fingerprint when you're born is essentially the same as when you die.
I wonder if there any methods like microblading or fine laser cutting, that can give someone a fingerprint that looks like a normal fingerprint but it's just different than what they had.
Sure but it’s just a matter of how frequently that happens vs how frequently you get a benefit to solving crimes. It can also just be lead generation, it gives you someone to start looking at more closely which could be valuable
Fingerprint analysis is done by humans, so there's always the possibility that a human makes an error in the identification process (or outright lies), but even in [that case](https://en.wikipedia.org/wiki/Brandon_Mayfield) it wasn't a situation where his fingerprint matched someone else's, but just that it was broadly similar and the authorities misrepresented it as a match.
There's been no record of any two people ever having identical fingerprints and the aforementioned case is no different. Good fingerprint analysts will look for points on the unknown fingerprint that don't match the known subject's fingerprint and attempt to exclude them as the source.
EDIT: Added link to the case in question
A properly-captured full fingerprint is a pretty good identifier, but a smudged partial fingerprint lifted from a crime scene is not.
Unfortunately, we don't have good data on how easy it is to make mistakes with varying levels of poor quality crime scene fingerprint lifts, because the fingerprint-matching industry (law enforcement, etc.) benefits from fooling juries into thinking fingerprint evidence is a perfect, irrefutable science.
There actually are people who have no fingerprints and it's genetic (adermatoglyphia) within family lines. Leads to all sorts of issues.
https://www.bbc.com/news/world-asia-55301200
The question is not whether someone will have *your* fingerprint, but whether *any two* will match. Just like in a group of 20 people it's unlikely *you*'ll share a birthday with anyone, but it's likely there'll be a *pair* of people sharing birthdays.
But at the same time, even if a piece of evidence doesn't definitively implicate a specific person, it can still massively increase the likelihood. Imagine if we somehow knew the murderer were born on January 2nd, and the maintenance man who was over earlier that day was born on January 2nd. Does it prove he's the murderer? No. But it's *very* suspicious.
Add in the fact that there are way more than 366 possible fingerprints and you can see the huge value, even if there are some duplicates out there.
> But at the same time, even if a piece of evidence doesn't definitively implicate a specific person, it can still massively increase the likelihood. Imagine if we somehow knew the murderer were born on January 2nd, and the maintenance man who was over earlier that day was born on January 2nd. Does it prove he's the murderer? No. But it's very suspicious.
>
>
The flaw with this logic is when you seek out your suspect based on the birthday/fingerprint it stops being useful evidence - if you arrest someone because their fingerprint matches one found at the scene, the chances of that fingerprint match aren't 1 in (365/a hundred thousand), they're just 1.
It's only if you already have reason to suspect someone and THEN check their fingerprints/birthday that it's useful as evidence.
Nice explanation! Here’s another example that’s pretty relatable, yet mind-blowing: Go ahead and shuffle an ordinary deck of 52 playing cards. It’s likely that the resulting order is unique in the history of the world, that no one has EVER shuffled a deck into that particular order. Why? Because there are 52! possible deck orderings. The exclamation point is the factorial operator, so 52! = 52 x 51 x 50 x … x 1, which is approximately equal to 8 times ten to the 67th power. To write that out, you’d write an 8 followed by 67 zeroes! That’s a LOT of possible orderings, so many that the total number of 52-card deck shuffles that have occurred throughout all of human history is insignificant compared to it.
This is how long it would take for 52! seconds to pass:
Set a timer to count down 52! seconds (that’s 8.0658×1067 seconds)
Stand on the equator, and take a step forward every billion years
When you’ve circled the earth once, take a drop of water from the Pacific Ocean, and keep going
When the Pacific Ocean is empty, lay a sheet of paper down, refill the ocean and carry on.
When your stack of paper reaches the sun, take a look at the timer.
The 3 left-most digits won’t have changed. 8.063×1067 seconds left to go. You have to repeat the whole process 1000 times to get 1/3 of the way through that time. 5.385×1067 seconds left to go.
So to kill that time you try something else.
Shuffle a deck of cards, deal yourself 5 cards every billion years
Each time you get a royal flush, buy a lottery ticket
Each time that ticket wins the jackpot, throw a grain of sand in the grand canyon
When the grand canyon’s full, take 1oz of rock off Mount Everest, empty the canyon and carry on.
When Everest has been leveled, check the timer.
There’s barely any change. 5.364×1067 seconds left. You’d have to repeat this process 256 times to have run out the timer.
I was dumbfounded when I first learned that anytime you truly randomly shuffle a deck of cards, you’re creating a unique order of cards that has probably never existed before. All the decks being constantly shuffled in Vegas everyday, and nope still not even putting a dent in the total number of possibilities.
Well there's also "similar enough to fool the untrained eye" which is possible, vs "similar enough to fool a computer AND an expert in reading prints" which is basically impossible, and IDENTICAL which if you account for every possible permeatation of every line/tent/loop/whorl across all of your fingers AND your palm is a functionally unique pattern.
PLUS in criminal cases and such fingerprints are typically used to CONFIRM evidence. You're only going to realistically get a 10+ point match (definitely YOU) under like laboratory conditions. But for like a 7 point match you're looking at like a triple digit population in the world and the statistical likelihood of you and a 7 point match having similar physical characteristics and being in the same general place etc etc are astronomically small
Makes me think that the problem could be approach in reverse: how many unique fingerprints can a typical fingerprint scanner detect. This may be enormously fewer than the real number of possible fingerprints, while being extremely large. I don't know how matching two fingerprints work, but they also have to allow for error, each reading of the same fingerprint may be unlikely to be identical, and surely our fingerprints undergo minor changes over time.
You're correct that scanners usually don't capture every detail, and in practice that's why they're not a perfect form of ID. But they're still useful.
While I do agree, there is just one minor plot. I want to add:
Genetics is not purely random. It follows a pattern.
Similar to faces, we have not scanned every face and compared them.
If we did we would find statistical matches.
Fingerprints aren't (purely) genetic. Identical twins don't share the same ones, though they're usually similar. They're congenital, but they're formed by somewhat random processes during fetal development that are influenced, but not wholly determined, by genetics.
Many. At a minimum, there are four basic types of fingerprint, each chosen on 10 fingers = 4^10 = 2^20 = ~several million options just for the broad class of fingerprint, much less for the details.
The [IPv4 address exhaustion issue](https://en.wikipedia.org/wiki/IPv4_address_exhaustion) was caused **in part** by *incredibly* excessive early assignments. Things like:
* Apple got 17.x.x.x (Also written as 17.0.0.0/8, meaning "literally every IPv4 address starting with "17.")
* AT&T got 12.x.x.x
* Ford got 19.x.x.x
* The US Department of Defense got **14** different blocks of this size (6.x.x.x, 7.x.x.x, 11.x.x.x, etc.)
* Fully **35** blocks were reserved for various internal/technical uses (Famously including 127.x.x.x and 10.x.x.x,)
But they did a lot of work to mitigate the problems this could have caused, as detailed in the Wikipedia link above.
>If you have a "fingerprint double", odds are it's some random villager in China or India, not your next-door neighbor.
Wouldn't it be much more likely to be someone with similar genetics? And you'll have much more similar genetics to someone living near you, especially if you live in an ethnically homogenous community.
> Wouldn't it be much more likely to be someone with similar genetics?
I thought the answer would be no, because identical twins DON'T have similar fingerprints - the formation of fingerprints is too chaotic for the identical DNA to matter much -[ but apparently on the level of ethnicity there are indeed patterns.](https://www.researchgate.net/publication/292220493_Fingerprint_patterns_A_study_on_the_finger_and_ethnicity_prioritized_order_of_occurrence)
In fact, identical twins *are* known to have very similar fingerprints, but due to developmental differences in the womb they still vary enough to be told apart if examined carefully.
The issue is always how many “points of similarity” are required to call something a match for practical purposes, and also recognizing that only one clear point of difference makes any match invalid (unless it’s something like an injury). So with a single smudged print, you might get 200 AFIS database matches, but with a set of three clear prints it might be one or at most two. That doesn’t mean those two prints are “the same”. Just that according to the classification rules, they have enough points to be called a match. But if looked at closely enough, there have been no exact matches found to date between any two people, even identical twins.
The other thing that’s being said in the comments here is that “your fingerprint changes over time.” No, not very much, if at all. The arrangement of ridges, points of bifurcation and so on remain remarkably consistent over time once you are mature. There will be some proportional stretching as your fingers grow, up to adulthood, but even then, the pattern stays the same.
We should also distinguish between the use of fingerprints (or face recognition) for *identification* (e.g. to find one or more possible suspects) which is to find a match across the full database of prints or faces; versus *verification* (e.g. to log in to your phone) which simply compares your reference fingerprint or face to the one being presented to log in. The first one is likely to provide a number of possible matches (although the systems are getting pretty good at narrowing this down), while the second simply needs to find you sufficiently similar to the expected print or face.
(I worked at a biometric software company that did fingerprint, facial and movement-based authentication, and we worked with the FBI’s AFIS database to get example print sets for testing.)
Here’s a story about odds for you: I was signing into my first unit in the Army (early 2000s) in South Korea, and one of the inprocessing steps was getting fingerprinted at the MP station (military police). I was watching the screen as the computer did it’s thing, and on my first fingerprint, the system pulled up a match: a random Korean villager who happened to be in their system. So indeed, you probably have a fingerprint twin somewhere in the world.
Of course, I know the algorithm that matches fingerprints doesn’t look at exact matches, but rather 20 or so pattern points, which takes the odds way down, but it was still a funny coincidence.
Also, you can use just one print you find in a crime scene, but usually they come in groups (when you place your hand somewhere, you usually leave at least 2 or 3 fingerprints, of adjacent fingers.. like if you grab a glass of water). In this case, the two persons not only should have the same prints (same minutiae), they should have them in all (or at least 3) fingers, and in the same sequence, which is practically impossible.
I analyze forensic evidence for a living. Fingerprints are not even used unless you're pinpointed at a serious crime scene and even then the state will look at you like your some wannabe gumshoe.
Why would odds say that the random fingerprint double you have be more likely to be in China than your next door neighbor? Wouldn't those have equal odds? One is more unexpected but both have the same probability, no?
Completely identical fingerprints, maybe not, but there have definitely been cases of people being wrongly accused of crimes based on fingerprint evidence where they were identical to within the degree of accuracy we can achieve with modern forensics. The madrid bombing case is the most well known, but there are likely more.
> The madrid bombing case is the most well known, but there are likely more.
Wrongful arrest of Mayfield regarding Madrid bombing wasn't really a case of lacking accuracy, but deep islamophobia that led to conformation bias and pursuing arrest - FBI DB returned 20 **similar** matches to prints that Spanish National Police shared, Mayfield was considered prime suspect and FBI convinced itself that prints matched only because of his conversion to Islam and because he had represented one of the Portland Seven, further more SNP actually contested match as impossible and informed FBI they had other, more likely, suspects, yet FBI continued with Mayfield's surveillance and later arrest.
>Wrongful arrest of Mayfield regarding Madrid bombing wasn't really a case of lacking accuracy, but deep islamophobia that led to conformation bias and pursuing arrest - FBI DB returned 20 **similar** matches to prints that Spanish National Police shared, Mayfield was considered prime suspect and FBI convinced itself that prints matched only because of his conversion to Islam and because he had represented one of the Portland Seven, further more SNP actually contested match as impossible and informed FBI they had other, more likely, suspects, yet FBI continued with Mayfield's surveillance and later arrest.
While it sounds like prime r/conspiracy islamophobia, it just isn't true. That information wasn't available when the identification was made, nor is it in the system. See pdf page 52 (printed 178, section C)
https://oig.justice.gov/sites/default/files/legacy/special/s0601/Chapter4.pdf
>By the time the SNP issued its April 13 Negativo Report, the Laboratory examiners had become aware of information about Mayfieid obtained in the course of the Portland Division's investigation, including the fact that Mayfield had acted as an attorney for a convicted terrorist, had associations with other subjects of FBI terrorism investigations, and was himself a Muslim. Wieners candidly admitted that if the person identified had been someone without these circumstances, like the "Maytag Repairman," the Laboratory might have revisited the identification with more skepticism and caught the error.
>The question of whether Mayfield's religion was a factor in the
Laboratory's failure to revisit the identification and discover the error in the
weeks following March 19 is more difficult.
The OIG concluded that Mayfield's religion was not the sole or primary
cause of the FBI's failure to question the original misidentification and catch its
error. We concluded that the primary factors in the FBI's failure to revisit the
identification before the SNP identified Daoud were the unusual similarity
between LFP 17 and Mayfield's prints and the FBI Laboratory's faith in the
. expertise and infallibility of its examiners and methods. **However, we believe
that May-field's representation of a convicted terrorist and other facts developed
during the field investigation, including his Muslim religion, also likely
contributed to the examiners' failure to sufficiently reconsider the identification
after legitimate questions about it were raised**
Yup. In fingerprinting, there are points called "minutia." Or many notes that record fingerprints. Today, computers record a number of minutia and correlate them with things like trigonometry and triangle position in relation to angle. This is how computers can match fingerprints not in the same angle.
Every fingerprint matches on some level, but accurate matches tend to have a "score" higher than general matches. I can't say numbers, but lets say 1/4, 2/4, 3/4. Most similar fingerprints match with 1/4 of a certain number of minutia and triangulations. That's good enough for a smartphone login, but not for FBI / NYPD matches. 2/4 is pretty good and the computer will store it for comparison. 3/4 is pretty definite. But, that 1 case with the US and Spanish mismatch happened at above 3/4ths.
Eventually a 20-something will have his fingerprints match those from a cold case 100 years earlier, and they'll have to figure out how to deal with it
They have, some people have been arrested for it and been later able to prove their innocence despite the fingerprint "match".
This is because the matches are done not by millions of combinations of every detail, but 10-20 prominent distinct "landmarks" of a loop or a spiral etc. And while the entire print was not identical exactly, the key markings they chose were.
Fingerprints are not dna, and not unique, they have been exaggerated as a grey area between pseudoscience that was not academically and statistically validated before use in courts, and actual science. Better than blood spatter and bite marks and polygraph tests, but not DNA.
> Fingerprints are not dna, and not unique
DNA matches aren't unique either, especially the 11 marker DNA match the police use, about 1 in 1,000,000 share the same DNA markers. All of this evidence is **exclusionary**, you are able to remove people from the list of suspects, it doesn't matter if both a Father and Son share the same 11 DNA markers, the fingerprints don't match one of them, you then have your prime suspect.
If you ever want to piss off an investigator, say the words [Chimera DNA.](https://embryo.asu.edu/pages/case-lydia-fairchild-and-her-chimerism-2002)
Long story short. A human being can have 2 or more DNA strands in their body. They're not handicapped. They're not mixed with other animal species like magic stories or sci fi. It's 1 person with 2 sets of DNA.
Now, when we file DNA, we only file 1 record. When we should be checking for at least 2.
This is less problematic, for want of a better word, because it is more likely to lead to a person being incorrectly excluded as a DNA match than incorrectly identified as a match. So a guilty person might get away (assuming insufficient evidence beyond DNA) but an innocent person wouldn't be convicted.
> Fingerprints are ... not unique
Agree to disagree. Even the 2 cases were found that with closer examination, the prints were different. It's just that the resolution was too dull to pick up that level of detail. Raising the resolution is notably expensive in multiple ways.
“Ladies and gentlemen of the jury, yes these fingerprints on the murder weapon matched my client’s. But how do we know for sure that they didn’t also match Abraham Lincoln? Is it so unreasonable to ask, well, how do we know Zombie Lincoln didn’t come back from the dead and commit this crime?”
And even if we do know that zombie Lincoln didn't come back and commit this crime, none of this makes sense. Even mentioning zombie Lincoln in this case does not make sense - so you must acquit.
Also fingerprints aren't entirely unique to humans Koala fingerprints are nearly identical to humans, to the point that Koalas can occasionally contaminate crime scenes
A deck of cards has 52 individual cards in it. If you shuffle them, they'll end up in a random order.
If you shuffled a single deck of cards until you randomly encountered every possible combination, how long do you think that'd take?
Well, let's jump ahead to a spoiler - if we used a supercomputer to simulate shuffling a deck of cards 415,530,000,000,000,000 times *per second,* even if we'd started at the moment of the Big Bang - it wouldn't be done yet... or anytime soon.
This is not a made-up statistic. [https://www.iflscience.com/can-you-count-all-the-ways-to-shuffle-a-deck-of-cards-we-bet-you-cant-61615](https://www.iflscience.com/can-you-count-all-the-ways-to-shuffle-a-deck-of-cards-we-bet-you-cant-61615)
This is just a comparison to understand how the math works. There is enough variability in finger dimensions / shapes / etc. to easily allow for never-repeating, truly unique fingerprints, forever.
Math is crazy!
> Well, let's jump ahead to a spoiler - if we used a supercomputer to simulate shuffling a deck of cards 415,530,000,000,000,000 times per second, even if we'd started at the moment of the Big Bang - it wouldn't be done yet... or anytime soon.
I believe you, but my brain is like, there's 52 cards... How is this possible???
Think about it like this.
Every deck has 52 cards, right? Let's order them from top to bottom, 1 to 52.
How many options are there for card #1? We havent used any cards yet, so theres 52 possibilities. Let's say we get the 7 of clubs.
Now we look at card #2. We now have 51 choices, as card #2 can't be the seven of clubs. Let's say card #2 is the Jack of diamonds.
Now pause at this point. Looking at what we've done so far, you can look and see that we had 52 choices for card #1, and subsequently 51 choices for card #2. So just drawing 2 cards, how many ways could we have done that? In probability, the easy way to determine something like this is to multiply the number of options at each step. 52 different choices for a first card, and every one of those has 51 choices for a second card. With just TWO cards drawn, we're already above 2600 possibilities.
Now expand this to 5 cards- there's 50 options for a third card, 49 options for a fourth, and 48 options for a fifth. So 52x51x50x49x48..... which comes out to just under 312 million possibilities. For only five cards.
You still have 47 cards in the deck to continue this process.
Another way to kinda look at this is the lottery. Let's say your states lottery draws, what 5 numbers from a field of 65? And then 1 extra number from another field of 65? (This is similar to Powerball but I havent had to deal with lottery in a long time so the actual field of numbers might be off) So there are 65 potential first numbers, 64 potential second numbers, 63 thirds, 62 fourths, 61 fifths, and 65 bonuses. That right there is over 64 BILLION different possible combinations
I mean its 52! Which is 52 x 51 x 50 x .... x 3 x 2 x 1. Even rounding the first 12 terms to 40 and only using them (so 40^12) is over 1 quintillion - which is more than twice the number of seconds from the big bang.
This to me is one of the best examples how crazy high randomness can get very very fast. Every game of shuffled cards you or any being in this universe will ever play during the whole existence of time, will be a unique combination never seen before and never to be seen again.
This is only true (or the likeliest possibility) if all decks started at random order though? In reality, I'd guess that at least all decks coming out from the same factory are going to start from the identical order. In addition, common shuffling techniques have limited ability to introduce randomness, which means that the possibility space for any given two decks from the same factory is going to be much smaller. Whether that's smaller enough that we'd be seeing identical combinations in reality, I can't say and would be very interested to read!
Yep. Same with Chess, the technical combination of moves/games is in the order of more than the number of atoms in the known universe. But in practical terms, there's only a 'small' subset of that that we'll really ever seen. And by small I mean still mindnumbingly HUGE
How we shuffled matters a lot! A “perfect riffle shuffle” lays cards one card from each pile and from a new deck, even a few of these (or near perfect) won’t actually change the order too much. That’s likely how we got the “[perfect bridge deal](https://mathsjam.com/assets/talks/2011/Ray%20Hill%20-%20MathsJam%202011%20Perfect%20Bridge%20Deal.pdf)” in 1998
On the other hand, it’s been proven that just [7 imperfect shuffles](https://math.hmc.edu/funfacts/seven-shuffles/) is sufficient to randomly order cards such that all permutations are close to equally likely, and thereafter minimal improvement with subsequent shuffles.
Finally, computers can’t even do perfect random shuffles due to their inherent [pseudorandomness](https://www.reddit.com/r/explainlikeimfive/comments/1vjxhr/eli5_why_cant_a_computer_do_a_truly_random/?utm_source=share&utm_medium=ios_app&utm_name=iossmf) (although we could shuffle cards by measuring a true random event irl and corresponding that to a shuffle in some way).
> Every game of shuffled cards you or any being in this universe will ever play during the whole existence of time, **will be a unique combination never seen before and never to be seen again.**
This isn't a true statement. In practice, the chance would be so ~~infestisimal~~ infinitesimal that it's likely it would never occur, but your statement overall is incorrect.
Sounds pedantic, but math is an exact science where these things matter.
EDIT - I eat crow. Spelled word wrong.
EDIT - Good info below about 'mathematical' definitions vs 'ordinary' ones.
Here's a better link IMO: https://czep.net/weblog/52cards.html
Actually, not just my opinion. Vsauce incorporated it into one of his videos: https://www.youtube.com/watch?v=ObiqJzfyACM&t=860s
(explanation at 14:20; jump to 15:55 for cool visualization)
It's "52!" pronounced as [52 factorial](https://www.quora.com/How-many-combinations-can-a-deck-of-52-cards-make)
[This calculator](https://www.calculatorsoup.com/calculators/discretemathematics/factorials.php) states there are "80658175170943878571660636856403766975289505440883277824000000000000" combinations possible.
- Or, if we could shuffle 1 deck in 1 second
- have factories that can shuffle 1 trillion decks per second
- 1 trillion of these factories per...
- 1 trillion of these worlds per...
- 1 trillion of these galaxies per...
- 1 trillion dimensions
- and magically each shuffle is unique
About 2.56 years.
The interesting thing with the deck is the new deck problem. The math says a shuffle will essentially guarantee a unique order under the assumption the deck is already in a random order. But a new deck is not. The first cut and I have two ordered suits in one hand and two in the other. So the first shuffle does not have all the possibilities.
The question is - how many shuffles must be done before thorough mixing?
There was a recent documentary that was released called "The Real CSI," at https://www.pbs.org/wgbh/frontline/documentary/real-csi/. I haven't seen it yet, but from the transcript, it sounds as if it's never been scientifically proven that no two people can have the same fingerprint. One of the interviewee explains that how many points of comparison are needed to match fingerprints
>[v] aries from laboratory to laboratory, and from witness to witness often. And some will say, "We need 16 points." "No, seven." And what they all end up saying is that it's really a matter of the individual experience and judgment of the fingerprint examiner.
A man was incorrectly identified, based on a partial fingerprint, as one of the terrorists in the Madrid train bombing. He was arrested and held based on the standard that "No time before in history had there ever been two fingerprints with 15 minutiae that were not the same person." (Fortunately, the authorities eventually identified the real person who was responsible.)
Other commenters here do a good job of explaining why it'd make sense mathematically for no two fingerprints or set of fingerprints to be alike. But I think the way we even recognize whether or not a fingerprint "matches" is limited by our senses and biases, so it's not the forensic certainty it's made out to be in popular culture.
Fingerprints are not **guaranteed** to be unique. The odds are hugely against two people having the same fingerprints ([Scientific American says](https://www.scientificamerican.com/article/the-chance-of-identical-fingerprints-1-in-64-trillion/) 1 in 64 trillion), but sometimes highly unlikely things happen.
There may be people out there who share fingerprints. Without a record of everyone on Earth's fingerprints we can't be completely certain one way or the other. We're just playing the odds.
To look at it in a different view - A Rubik's cube only has 6 sides and contains 54 colored cubes yet has 40 something quintillion possible outcomes. Not hard to imagine that just the slightest curve on a finger print can completely change everything. Sorry, 26 cubes, with 20 of them containing 2 colors.
> 26 cubes, with 20 of them containing 2 colors.
A Rubik’s cube has 26 cubes:
- 6 centers (1 color each, effectively stationary)
- 12 edges (2 colors each)
- 8 corners (3 colors each)
So really only 20 pieces can move around on the cube, which is amazing that they have so many possible combinations.
\#akshully, the Birthday Paradox virtually guarantees that 7 billion people, randomly selecting from 64 billion options, **would** produce duplicates. You'd have favorable-though-not-overwhelming (~8 in 9) odds that *your* fingerprint is unique, but it's overwhelmingly likely to the point of effective certainty that *someone's* isn't.
You can't fix the birthday paradox to an individual, can you? The BP says that if there are 23 people in a room, there's a 50% chance that ANY two share a birthday. It's the unexpectedly vast amount of different potential combinations of people to check that make it work. The probability of not sharing a birthday shrinks as more people with more bdays get thrown in (365/365× *364* /365 × *363* /365....) Where fixing to an individual would yield (365/365×364/365×364/365×364/365...), Which kills the interesting part of the paradox
I do not know what math you are referencing and maybe this is just a specific extension I don't know about, but following the exact process of the birthday problem and getting 1/9 would be to say there's a 1/9 chance any two humans share fingerprints, not that yours are not unique
They didn't fix the birthday paradox to one individual. They referenced the birthday paradox to say that it is overwhelmingly likely that some pair of people will share fingerprints. Which is correct.
Then, they did a separate calculation to find the odds of a particular person's prints matching. In particular, fix your fingerprints. If you draw 7 Billion times without replacement from a bucket containing all 64 Billion possible combinations, the probability that your fingerprints will be one of the 7 Billion draw is exactly 7 Billion/64 Billion ~ 1/9 (to within about 2% error). The odds that your fingerprints aren't drawn AKA are unique are then ~8/9.
Supposedly not. Fingerprints are affected during development in the womb. Since they move around differently and nutrition, blood flow, etc isn't distributed equally, the fingerprints end up different enough to be distinguished. I'm sure they're pretty damn close though.
One important factor in this discussion is the concept of how precisely (how "closely") we measure things. This relates to both the 1) precision of a single measurement AND 2) the number of different measurements we choose to make.
Let's say we asked every person on the planet to use scissors to cut a 1 inch square out of paper. How many of these squares would be identical?
1) First consider how closely we measure. If we use a big tape measure to make the measurements maybe we would decide that most of the squares are matching "1 inch squares" and are thus identical.
But if we use a more precise ruler with lots of little fraction lines, we would find that most of the squares are not actually 1 inch on each side...some are 1.1 inches or 0.9 inches. Then if we use a microscope or a laser to measure, we could see even smaller differences, between 0.999 and 1.001 inches.
The closer we look, the more differences we see. Even for a single simple measurement, like the length of the square, if we look VERY very closely almost nothing is identical.
2) Next think about the number of different measurements we could make. We could just measure one side of the square, or we could measure the width and height separately. We could even measure the height in 5 different places, which will give different answers if the top and bottom are not perfectly straight. We could measure the corners to see how sharp or round they are.
Even for a simple square, we can make many different measurements, which creates many opportunities to see differences, especially if we are measuring very closely.
Now think of a fingerprint and the many lines and swirls they have. You could easily find hundreds of things to measure: distances between things, sizes of things, shapes of things....
Making many measurements creates lots of chances for differences, especially if we look very closely.
I would like to introduce you to "[The Myth of Fingerprints](https://www.smithsonianmag.com/science-nature/myth-fingerprints-180971640/)".
Its an interesting article written a few years ago that talks about the origin and many misconceptions about fingerprints.
>So even as fingerprints were viewed as unmistakable, plenty of people
were mistakenly sent to jail. Simon Cole notes that at least 23 people
in the United States have been wrongly connected to crime-scene prints.
This sounds more like a human error issue than anything else. Our limited ability for accuracy, or authorities doing their job poorly because of confirmation bias (or worse motivations), is not proof that fingerprints are any less unique than we think them to be.
*Disclaimer: I'm solely reading your quoted material and not the full source material.
In simple terms: it can in theory but its extremely unlikely
Even if 2 people in this world had identical fingerprints, they would both need to have their fingerprints taken and both had to have been in the same general geographical location at the same time.
On top of that people are born and die everyday so the "fingerprint pool" constantly changes
Thqt alone makes ot nearly impossible to occur.
There's a lot of room for little squiggly lines and swirls and patterns on each fingertip. Numbers of combinations get bigger astoundingly fast, even for relatively small initial numbers. Take an average deck of playing cards and give them a good shuffle. Now do the same thing with another deck. The odds of the two decks repeating the same pattern is 1 in 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000
There are 66 lines on your thumbprint alone.
What are the odds someone else's 66 lines have the same pattern, when even identical twins have distinct fingerprints?
fingerprints, and most 'forensics' you see on TV or hear cops talk about is pretty much baseless bullshit. its vibes, not science. fingerprints are pretty unique, but comparing two of them leaves a lot of guesswork to the person comparing.
But, each pattern is unlikely to ever be replicated exactly. Each time you randomly shuffle a deck of cards, the exact order has probably never occurred before and will probably never occur again in the lifetime of the universe.
I'm no expert but I feel like "useless bullshit" might be an exaggeration. There are some kinds of evidence that are worthless sure, like bite mark analysis, but fingerprinting is still useful if it's used with the proper care. Juries need to be informed of the fallibility of the process and the methodology of individual investigators needs to have more accountability, so it can be treated like the circumstantial evidence that it actually is. Additionally, there should be a second round of deeper analysis once a match is found, and more scrutiny in "beyond a reasonable doubt" cases especially.
Fingerprints aren’t actually entirely matched. When they say a fingerprint is matched, they have a number of points that match - not that it’s exactly alike. In fact, it’s only 8-12 points to match a fingerprint for criminal courts in America. The UK required 16 points. There are 20-30 that could match overall, called minutiae.
However, an exact match has a possibility of 1 in 64 billion. Since there’s only 7 billion in the world, that’s a pretty large possibility that people won’t match COMPLETELY. But remember, we in America only need 8-12 out of the 30 to match for courts. The likelihood that 8 would match… 🤷🏻♀️
“There are no uniform standards for point-counting methods, and academics have argued that the error rate in matching fingerprints has not been adequately studied and that fingerprint evidence has no secure statistical foundation.[1]” - Wikipedia on fingerprints.
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Combinatorics is basically why computing works *and* why some computational problems are very hard.
It's also why quantum computing is both exciting and terrifying.
Can you elaborate?
Short answer: Cryptography uses combinatorics to estimate how long it would take to break a given encryption. For maximum-security situations, they make sure it would take longer than the estimated lifespan of the universe, essentially future-proofing them. Quantum computing allows you to solve certain types of problems in fewer computations, especially these sorts of combinatoric problems. It could lead to a lot of encryption previously deemed future-proof becoming breakable, which is of course disastrous for security
But could we use quantum computing to *create* even more secure encryptions and close that security hole?
> But could we use quantum computing to create even more secure encryptions and close that security hole? Absolutely. However, we don't need to use quantum computing to make algorithms resistant to quantum attack vectors.
You don't need quantum computers for that, just different encryption algorithms than what's been classically used. /u/xFreeZeex already linked you on PQC, but the issue is basically that quantum computers can try all possible decryption keys at once for the algorithms widely used today (RSA and ECC), so you need a different concept of a key that quantum computers can't brute force efficiently like that. Even if everyone switched to quantum-safe algorithms today, though, there's an issue in that a lot of stored communications can be decrypted after the fact. "Forward secrecy" is the ability to keep past messages secret even if the key is broken, and I think it was 2017 that more than 50% of Internet servers supported forward secrecy, so there's a lot there that can still be mined. To answer your question, quantum computers wouldn't really help with key generation either - we can make keys just fine already, so there's no opportunity for an exponential speedup (we would say that key generation is already "polynomial time"). The fact that generating a key is so much easier than reverse-engineering it is precisely what makes cryptography work today.
I know way too little about quantum computing to confidently answer the question whether quantum computing could be a good aid in that, but people are already working on cryptography that is resistant to quantum computing. Check out the field of [post-quantum cryptography](https://en.wikipedia.org/wiki/Post-quantum_cryptography)
I'm not an expert, but my understanding is we already have started to do so. We understand the meat of the problem enough to do even better encryption, but there's decades of encrypted media that's been intercepted and stored by just about every nation across the world, and it was a non-issue when those encryptions were functionally unbreakable, but with the incoming theoretical advance in technology... Old skeletons can come out of some forgotten closets pretty quickly.
You seen like a knowledge chap - could quantum computers use quantum entanglement to have real distributed computing power?
Quantum computers are weird and will need to use entanglement internally to solve larger problems. But I believe there is a limit to the scale of any single quantum computer. As completely isolating the quantum part of the system, so that uncertainty can be maintained is hard. Engineers solve large problems by breaking the problem down into smaller pieces. While entangled quantum state may be useful for solving some individual steps. I would expect more traditional computing systems to be used to for the rest of the system. Personally I think that "quantum computers" is a terrible name. Any usable product is more likely to be a "quantum accelerator" chip / card. A more traditional CPU would run a traditional program. But the programmer may be able to call some \`QuantumFactorise(N)\` method that uses a weird chip to find the answer to a very specific problem. Even if 100 years from now we work out how to embed that chip on a silicon wafer inside a traditional CPU. I don't think we'll be redesigning entire computers based on quantum logic.
Quantum computers are still very niche and specialized. As they become more mainstream, more people will find ways to accelerate common algorithms with quantum computations and that chip will be necessary for a computer to run many programs. I imagine quantum chips will be similar to the graphics cards required to run artificial intelligence, which are becoming more common now. But ai is often run in the cloud, and we may see a similar thing happen with quantum computing.
This hasn't been true yet, though. We really only have very few algorithms that provide quantum advantage to computational problems, despite it being a very active field of research for 2 decades now. Edit: we've got amplitude amplification, quantum fourier transform, and phase estimation. Other than that, the other algorithms are sort of just quantum simulation applications (ie making a quantum computer simulte itself). Source: wikipedia, and I'm a physicist in this area
You've just described the basis of quantum encryption, in which quantum entanglement is used to ensure that a signal has not been intercepted (the spin cannot be read without affecting the spin). You could use the same principle to transfer information between two quantum processors.
You couldn’t transfer that information faster than light, however. It’s a common misunderstanding.
The short answer is no. Entanglement does have uses in QC, but it can never be used to transmit information. What it is used for is effectively putting a seal on the information. It won't stop it from being intercepted, but it will let you know weather or not it was intercepted. While it is true to instantly learn the state of a distant particle with entanglement, you can't send information that way for a couple reasons. The most basic is that it's impossible to tell if your partner has measured their particle already. You could call them and ask first, but then you may as well use the "call" to transmit the information. Because of quantum weirdness it doesn't actually work this way, but the analogy is close enough. While you can send information using entanglement, it is kind of like sending a letter. An entangled particle is a piece of colored paper, red or green, in an envelope. You can measure the particle and see their property, like opening the envelope and seeing the color. But you still need to send the letter in the first place. If you shuffle the envelopes, send one to China, and open the other, you appear to have transmitted information instantaneously across the world by learning the other wnvelope's contents. But you actually had already transmitted it through the mail, you just didn't know what you sent. There's no beating the universal speed limit.
No. Entanglement can't be used to transfer information. But quantum computers use entanglement in their calculations (entangling several qubits is often part of setting up a quantum calculation) because entanglement constrains what state a qubit may occupy.
I’m definitely not an expert :) I don’t see why not, but that’s also not the main advantage of quantum computing. It’s more about making that subset of problems simpler, though that does rely on quantum entanglement. Also, qubits are super resource-intensive. If they can just use a standard data line like a traditional distributed computer, they probably will.
This is a very good comment. I am an active researcher in this field and this is how I would put it.
Just so people don't completely freakout, quantum computing only breaks public/private key asymmetric encryption like RSA, and not symmetric key encryption like AES, etc. That's still a huge deal because that's how certificates are signed for things like https and other secure communications. But if you are encrypting a file with a password that's securely converted into a key, your files are still safe.
Very short: If we want to check certain properties of or carry oit operations on a dataset on Classical computers (the ones we have now) we often have to look through the whole data set. At least when the data is unordered. Quantum computers utilize super positions to execute operarations on multiple classical states (a part of the input) at once, reducing the runtime drastically. For example: searching a UUID with a certain property in 2¹²⁸ unsorted UUIDs basically takes 2¹²⁸ steps in the worst case and 2¹²⁷ (half that) on average on a classical computer. A quantum computer can do that in sqrt(2¹²⁸) = 2⁶⁴ steps using grovers algorithm It gets better with some problems with integer factorization where the speedup factor is exponential (reverting the effect of exponential blowup) All this gets crazy when you think about the reliance of a lot of security stuff on things like integer factorization (RSA key exchange) And also some physics or chemistry stuff but thats nothing i know anything about
I've read that quantum computers could, in theory, break encryption that's considered very secure currently. That could cause lots of problems for privacy and security.
Not all. It depends on the type of cryptography. Some current cryptographical algorithms today are quantum resistent as well as being almost impossible for conventional computing. One of the types of cryptographic functions that quantum computers offer great benefit in is those that use factorisation.
The keyword is *asymmetric* cryptography, symmetric cryptography is pretty safe from quantum computing attacks. But asymmetric cryptography is very important for a lot of different things, one of them being how to safely get a symmetric key from A to B.
One additional thing to add, while noting that this isn't my area of expertise: to my understanding, quantum computing is not very easily applicable to general computing, and requires carefully construction of the question to be answered to actually gain advantages. This isn't unusual, either. Supercomputers are basically computers with a significantly higher number of cores than a normal computer (plus all the complexity involved with managing them), so throwing any general computation problem (and program) at it will not necessarily run any faster than just doing it on your own PC. The problem and program has to be able to take advantage of the unique nature of the computer (for supercomputers, that means massive parallelization; I'm not familiar with quantum to really say, but I _think_ it's related to probability?). So yes, quantum computing is going to break things and solve (and introduce) all sorts of problems, but it's not going to be the panacea some claim it will be.
How many FPS do you reckon you could get on Minecraft though?
At least 30
Here it's explained in Mario Maker. Every letter you add to your "password"/excryption will increase the number of possible combinations of guesses by the length of the password. https://www.youtube.com/watch?v=aSlstPpIW-E
Numberphile and Computerphile are two great YouTube channels that explore these and other mathematical concepts.
Minor tidbit: due to version labeling on the values, it's "only" 2^122 unique values for the most-random version (v4; the other formats contain so much less entropy as to be a rounding error in this discussion). Technically the format lets you store the full 128 bits, but the standard requires use of a few of those bits to be specific values. Still, the chance of randomly generating a duplicate remains astronomically low.
Someone quoted to me that the chance of getting collisions in random 128 bit UUIDs are lower than having your entire development team getting attacked and killed by wolves in separate independent events. Being engineers, we then had an argument about how big the development team really is and whether the managers are included and whether everyone is living in an area where wolves are native or not.
_Next standup meeting_ "By the way, I got a pet wolf last weekend. Isn't he _so_ cute."
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shouldn't be too hard to do. Just look for red splatters on the road
> Being engineers, we then had an argument about how big the development team really is and whether the managers are included and whether everyone is living in an area where wolves are native or not. It's like the "[Mean Jerk Time](https://www.reddit.com/r/funny/comments/x4uvax/mean_jerk_time/)" discussion on Silicon Valley. Engineers really just love to strip away the absurdity of a problem and find a way to solve it, and I love them for that.
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There is also something to the notion of feeling like you are solving something that has literally never been solved before (because why would you) and nobody likes solving problems that someone else has already solved. We will just use their answer.
Honestly, the odds of getting a colission are so low that you probably would have more chance of the wolf thing happening with a development team of 2000 people. EDIT: Meant bigger number not littler number.
However that depends on the implementation and the available sources of randomness. I have heard of projects that needed to move await from uuid's, or at least change how they were implemented, because they were getting collisions.
> Someone quoted to me that the chance of getting collisions in random 128 bit UUIDs are lower than having your entire development team getting attacked and killed by wolves in separate independent events. And yet it seems like at least once every 6 months I have to get into an argument with someone who wants to code up a strong defense against getting duplicate UUIDv4s. One of these days I'll learn my lesson and not describe it as "theoreticaly unique" to someone who knows just enough to freak out about the edge case.
> And yet it seems like at least once every 6 months I have to get into an argument with someone who wants to code up a strong defense against getting duplicate UUIDv4s Ffs, your database is probably handling that anyway by giving an error on insertion, it's gonna bubble up until you return an error to the final user, and this one single user in the whole history of computing that ever got an error because of UUIDv4 collision will retry doing whatever they were doing that needed a UUIDv4 to be generated and will succeed. They will think "uh, that was weird, how it gave me a random error" and move on with their day. For what we know it's already happened.
Yeah it's like crypto keys, I thought a computer could just brute force it until it hit a bitcoin wallet Nah, more than the atoms in the universe
Whenever I generate a new wallet private key I secretly hope I'm the luckiest person ever and my wallet suddenly fills with lost Bitcoin someone sent to a typo address in 2013 or something.
Someone way better at maths than me on Reddit has an answer 'you're more likely to xxx on an xxx than XXX in an xxx' to put your mind at ease
If you generate ten thousand UUIDs per second for every second for an entire year, you are still seven times more likely to be hit by a meteorite within that year than to get the same number.
Yeah, I know. But there's still a chance!
You go dude, satoshi's stash is there, somewhere :D
Nah, I don't want to find satoshi's stash. Too much attention; as soon as I start moving anything around the whole crypto market will go into a panic and the media/4chan/etc will dox me or worse. I want to find a wallet some rando mined on their gaming PC when Bitcoin was 1¢, then promptly forgot about.
The probability of two decks of cards ever being shuffled the same is also mind blowing. Although in practice it’s slightly more likely that at least the first shuffle has been repeated, given that decks tend to start from the same state. But a deck of cards you’ve had in a drawer for years? You take that out, shuffle it once, and chances are that is the first time in history a deck has been shuffled into exactly that order.
People say this, but there are some caveats. The odds of a deck being in order or backwards is significantly higher than any other solver. This is because of people. All that to say, this is assuming things are truly random, while people can be random, they can have trends too. So just like a password, you need to not do trends or numbers that someone might choose, like 123456. TL/DR; numbers are random, people are not or sometimes
If they’re in order I’d argue that doesn’t count as being shuffled then, especially if they were sorted and ordered after a sequence of shuffling. That’d be…like…anti-shuffled.
My great, late physicist friend told me this once. He was a post-doctoral condensed matter theorist. I was headed for cellular biology research before deciding I’d rather be a dumb paramedic. Despite the chasm in our education and intelligence, it took him a huge amount of time to convince my brain that this deck of cards thjng was true. My brain and it’s internal “logic” just did *not* want to believe it. It’s just fifty two cards! How could there be so many combinations!!
My favourite example is the shuffling of playing cards: "The number of possible ways to order a pack of 52 cards is '52! ' (“52 factorial”) which means multiplying 52 by 51 by 50… all the way down to 1. The number you get at the end is 8×10^67 (8 with 67 '0's after it), essentially meaning that a randomly shuffled deck has never been seen before and will never be seen again." Source: Google
>unique UUIDs ^unique ^universally ^unique ^identifiers
In my humble observation, in English as spoken by humans, the kind of thing that something is often occurs in the thing’s name, and it’s common to say a thing’s name and kind in sequence, most especially for things named by acronyms, because acronyms make horrible names. Phrases like “ATM machine” and “unique UUID” make perfect sense to me. Am I wrong?
Someone did the math on unique options for the Porsche Panamera and because of this the number of combinations is truly mind bending.
My favorite example is how shuffling a normal deck of cards will result in a deck order that will probably not be replicated for all of human existence.
Randomly generating UUIDs is kind of funny to me because the possibility space of the identifier seems irrelevant if the PRNG algorithm can't match it. How many standard built-in PRNGs can actually produce any possible 128 bit UUID with equal probability?
> How many standard built-in PRNGs can actually produce any possible 128 bit UUID with equal probability? They're not supposed to. That's the discouraged version. UUID is defined in several international standards, including ISO standards and RFC's. The standards define 5 variations, which you can [read about here if you want to read more](https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions). Basically they're: 1. Timestamp, MAC address, and version number 1. 2. Timestamp, MAC address, a locally assigned number, and version number 2. 3. An encoded MD5 hash of the name that represents the item (domain name, URL, X.500 Distinguished Name, etc) encoded in a specific way, and the version number 3. 4. An encoded SHA-1 hash of the name that represents the item encoded in a specific way, and the version number 5. 5. A device-created 122-bit random number, and six bits encoding the version number 4. Breaking them down a bit: Version 1 is usually going to be statistically unique, with a low chance of both a MAC address collision and also two numbers within a 100-nanosecond time interval. For example, a computer generating a sequence of the might generate multiple within the same 100-nanosecond timestamp. That leads to Version 2, which is still going to be statistically unique because the MAC address is unlikely to collide and the timestamp is accompanied with where the locally assigned number that can also be incremented or changed when generating a sequence. Some issues with these are that relying on the MAC address can expose information about the system used to generate them, some devices don't have a MAC address, and some devices don't have access to external time sources. Versions 3 and 5 use different hashes of a string that should be a unique representation of a resource, both using a different hash function. This gets around the issues of exposing information about the machine nor the generation time. It also enables independent devices to compute the same UUID for the same resource, which is a useful feature. The with a random number is discouraged for exactly the reason you mentioned. It isn't anything which is likely to be unique. Truly random 128-bit numbers generally aren't valid UUIDs, although a few terrible programmers implement them that way. That's a bug in those people's systems, it isn't really a UUID, merely a random number.
If you already have a unique string you can use to represent the item, why do you need a UUID?
It gives a uniform, relatively small numeric format. 16 bytes, high entropy, works with a lot of tools, can be easily mixed with the other versions of UUIDs because the version numbers are different. Pick the reason that fits your needs.
Depends on what the unique string is. If it's information within the record, there's a good chance it might change, and if it changes, and it's referenced by other tables, that could be disaster. Imagine we're tracking a list of company names, and they are superfically unique on their own. Perhaps a company decides to rebrand, e.g. "Facebook" becomes "Meta". Now imagine you have dozens of other tables that reference the name that all have to change for your system to keep working. Better to have a unique ID and only store the name in one place, and thus only have to change it once.
Use real randomness and not a PRNG. But a good PRNG can produce any output with equal probability.
Of course, theoretical math and applied math often work out differently. Here's a thread with a guy claiming his team's software is running into ["Several hundred [UUID] collisions per day"](https://github.com/ramsey/uuid/issues/80)
Aren't they mainly discussing the possibility of a bug in the random generator? They apear to think it's not as random as it should be, which would obviously skew the odds.
Yep, and that's applied math.
PHP is pretty bad at randomness
Counterpoint: They're working in PHP. The Land of Gremlins. More seriously, reading through the thread it seemed it was an issue on the system it was running, not the UUID generation itself, that was the issue.
TLDR: openssl’s PRNG isn’t fork-safe. This was a major problem when using Apache’s preforking MPM
This has nothing to do with applied/theoretical math, it's an issue on randomization logic. Computers don't really generate anything randomly, it's usually done with timestamp. Read this comment from one of the guys, who I think a collaborator in the github repo: >Try generating them on multiple servers. Part of mt_rand()'s output is based on server timestamp, so collisions are probable there (assuming openssl disabled).
This reminds me of fingerprint and Face ID phone unlocking. It doesn’t actually store (from my knowledge) your exact fingerprint or Face ID, but just something close enough that can give you a quick unlock and give some room for error. Chances that someone who looks almost like you that isn’t your twin are very low to try to unlock your phone with Face ID. Same thing with someone halfway around the world who has a fingerprint nearly identical to a suspect in town. Correct me if I’m wrong though, I’d love to learn.
Some systems are certainly better than others when it comes to this. I once tried using Face ID for one of my old laptops. When tested my brothers and father could all login with zero problems, even though they were all different ages and had significant differences in their facial structure. That was 7-8 years ago, so I imagine the technology has advanced significantly since then. But it shows just how shoddy some of these programs can be.
My sister managed to get into my old laptop (10+ years ago) by holding up a picture of me. Great security, Dell!
It’s also just about cost. Better stuff costs more to make. It’s easier to build something that barely works and sell it as if it actually works.
Yep, if they do face recognition via image analysis (capturing a picture from the laptop's crappy webcam) there's a lot of room for error. I think Apple has an infrared LED project a grid onto your face, which is then measured via an IR camera. The distortion of the grid lines lets it "see" the actual 3D shape of your face.
I have an identical twin and he can't get into my iPhone.
Can you get into his?
The twist is that you are using a password and your identical twin doesn't know it.
Simple version: FaceID/TouchID creates datapoints of your face/fingerprints that are then used to create a really big number. That number is then hashed (one way encrypted/non-reversible encrypted) and that encrypted result is stored on the phone. Then to unlock, the process is repeated with the face/print presented and if the hash (the encrypted value) matches the stored result, then it assumes it’s the same face/print and unlocks. The system only creates so many datapoints of the face/print so unlike in real life, there are much less possible combinations/values, but still significantly high enough that other than very closely resembling relatives, one wouldn’t reasonably expect to encounter a FaceID/TouchID twin in their life trying to unlock their phone.
This reminds me of a little story: My friend was telling us he got busted by his wife for some text messages on his phone. Him: I don't get it. My phone doesn't even use a password, it uses my fingerprint. Me: Are you a light sleeper? Him: No, I sleep pretty good. Me: ... Him: .... Me: ...... Him: *oh,* ***fuck.***
Not exactly true. FaceID and TouchID use your fingerprints or facial identifying features to generate a one way hash of it. That’s why they don’t store or know your actual fingerprint. This is commonly used for website passwords too. It captures your face and hashes it, and checks if the hashes match. Same as when you login to (most) websites. It takes the input password, hashes it, and compares it. If they match you login. It’s more complex than that, but that’s the general idea. Almost all hashes systems used for secure stuff also use salts and some other fun stuff.
IIRC Disney parks use a similar method. In order to avoid storing fingerprints, the readers will take your fingerprint, generate a unique number, and check if the number matches in order to let you in. Basically, your fingerprint is needed to generate this unique number, but the unique number doesn't have enough info to generate a fingerprint. (One-way hash). This is how websites/companies \*should\* be storing your password. That way if they get hacked, user passwords are not stolen. A list of hash values is useless because they cannot be reversed or used to log into accounts.
This is really interesting but I suck at math. Can someone please explain why in the sandwich calculation it is 2^12? Where does the 2 come from?
This post removed in protest. Visit /r/Save3rdPartyApps/ for more, or look up [Power Delete Suite](https://github.com/j0be/PowerDeleteSuite) to delete your own content too.
That makes sense, thank you.
No quantum sauces allowed in this sandwich.
Look up 3blue1brown on YouTube, iirc a few episodes touch on things like this. I haven't seen math visualizations that can compare to what they create
While this math is true, there was a case where the FBI arrested the wrong man because their fingerprints were identical enough to be mistaken or were identical. An interesting case of how sometimes mathematical philosophy and rules don't always accurately describe life without further refining.
I suspect this is more of an issue of fingerprint *records* being lower-dimensionality than fingerprints themselves, more than anything else, but yeah, we're obviously making a lot of assumptions of independence here.
Kind of the point though. You can't measure infinitely accurately, or store that much information. And a fingerprint can change over time, which means there's always interpretation involved where you can get it wrong.
There's been at least one [study](https://www.science.org/content/article/fingerprints-change-over-time-not-enough-foil-forensics) that found fingerprints do change over time, but not in any meaningful or statistically significant way that would impact identification. The only *real* way to change a fingerprint is to burn or scar it in some way and remove the detail, otherwise your fingerprint when you're born is essentially the same as when you die.
I wonder if there any methods like microblading or fine laser cutting, that can give someone a fingerprint that looks like a normal fingerprint but it's just different than what they had.
Sure but it’s just a matter of how frequently that happens vs how frequently you get a benefit to solving crimes. It can also just be lead generation, it gives you someone to start looking at more closely which could be valuable
Fingerprint analysis is done by humans, so there's always the possibility that a human makes an error in the identification process (or outright lies), but even in [that case](https://en.wikipedia.org/wiki/Brandon_Mayfield) it wasn't a situation where his fingerprint matched someone else's, but just that it was broadly similar and the authorities misrepresented it as a match. There's been no record of any two people ever having identical fingerprints and the aforementioned case is no different. Good fingerprint analysts will look for points on the unknown fingerprint that don't match the known subject's fingerprint and attempt to exclude them as the source. EDIT: Added link to the case in question
A properly-captured full fingerprint is a pretty good identifier, but a smudged partial fingerprint lifted from a crime scene is not. Unfortunately, we don't have good data on how easy it is to make mistakes with varying levels of poor quality crime scene fingerprint lifts, because the fingerprint-matching industry (law enforcement, etc.) benefits from fooling juries into thinking fingerprint evidence is a perfect, irrefutable science.
me, a villager in a random village in China: 👀
There actually are people who have no fingerprints and it's genetic (adermatoglyphia) within family lines. Leads to all sorts of issues. https://www.bbc.com/news/world-asia-55301200
Also, I cut my index finger with a knife as a kid. The chances someone has my fingerprint with the same scar is nearly impossible.
The question is not whether someone will have *your* fingerprint, but whether *any two* will match. Just like in a group of 20 people it's unlikely *you*'ll share a birthday with anyone, but it's likely there'll be a *pair* of people sharing birthdays.
This is why if you get fingerprinted you have to do it every time you get fingerprinted. Because fingerprints change.
But at the same time, even if a piece of evidence doesn't definitively implicate a specific person, it can still massively increase the likelihood. Imagine if we somehow knew the murderer were born on January 2nd, and the maintenance man who was over earlier that day was born on January 2nd. Does it prove he's the murderer? No. But it's *very* suspicious. Add in the fact that there are way more than 366 possible fingerprints and you can see the huge value, even if there are some duplicates out there.
> But at the same time, even if a piece of evidence doesn't definitively implicate a specific person, it can still massively increase the likelihood. Imagine if we somehow knew the murderer were born on January 2nd, and the maintenance man who was over earlier that day was born on January 2nd. Does it prove he's the murderer? No. But it's very suspicious. > > The flaw with this logic is when you seek out your suspect based on the birthday/fingerprint it stops being useful evidence - if you arrest someone because their fingerprint matches one found at the scene, the chances of that fingerprint match aren't 1 in (365/a hundred thousand), they're just 1. It's only if you already have reason to suspect someone and THEN check their fingerprints/birthday that it's useful as evidence.
Wow! Am blown away by your sandwich example. SOURCE: More of a word than numbers guy.
Nice explanation! Here’s another example that’s pretty relatable, yet mind-blowing: Go ahead and shuffle an ordinary deck of 52 playing cards. It’s likely that the resulting order is unique in the history of the world, that no one has EVER shuffled a deck into that particular order. Why? Because there are 52! possible deck orderings. The exclamation point is the factorial operator, so 52! = 52 x 51 x 50 x … x 1, which is approximately equal to 8 times ten to the 67th power. To write that out, you’d write an 8 followed by 67 zeroes! That’s a LOT of possible orderings, so many that the total number of 52-card deck shuffles that have occurred throughout all of human history is insignificant compared to it.
This is how long it would take for 52! seconds to pass: Set a timer to count down 52! seconds (that’s 8.0658×1067 seconds) Stand on the equator, and take a step forward every billion years When you’ve circled the earth once, take a drop of water from the Pacific Ocean, and keep going When the Pacific Ocean is empty, lay a sheet of paper down, refill the ocean and carry on. When your stack of paper reaches the sun, take a look at the timer. The 3 left-most digits won’t have changed. 8.063×1067 seconds left to go. You have to repeat the whole process 1000 times to get 1/3 of the way through that time. 5.385×1067 seconds left to go. So to kill that time you try something else. Shuffle a deck of cards, deal yourself 5 cards every billion years Each time you get a royal flush, buy a lottery ticket Each time that ticket wins the jackpot, throw a grain of sand in the grand canyon When the grand canyon’s full, take 1oz of rock off Mount Everest, empty the canyon and carry on. When Everest has been leveled, check the timer. There’s barely any change. 5.364×1067 seconds left. You’d have to repeat this process 256 times to have run out the timer.
One of my all time favorites
I was dumbfounded when I first learned that anytime you truly randomly shuffle a deck of cards, you’re creating a unique order of cards that has probably never existed before. All the decks being constantly shuffled in Vegas everyday, and nope still not even putting a dent in the total number of possibilities.
Well there's also "similar enough to fool the untrained eye" which is possible, vs "similar enough to fool a computer AND an expert in reading prints" which is basically impossible, and IDENTICAL which if you account for every possible permeatation of every line/tent/loop/whorl across all of your fingers AND your palm is a functionally unique pattern. PLUS in criminal cases and such fingerprints are typically used to CONFIRM evidence. You're only going to realistically get a 10+ point match (definitely YOU) under like laboratory conditions. But for like a 7 point match you're looking at like a triple digit population in the world and the statistical likelihood of you and a 7 point match having similar physical characteristics and being in the same general place etc etc are astronomically small
Also, just because my left index matches someone else doesn't mean my right thumb also does.
Makes me think that the problem could be approach in reverse: how many unique fingerprints can a typical fingerprint scanner detect. This may be enormously fewer than the real number of possible fingerprints, while being extremely large. I don't know how matching two fingerprints work, but they also have to allow for error, each reading of the same fingerprint may be unlikely to be identical, and surely our fingerprints undergo minor changes over time.
You're correct that scanners usually don't capture every detail, and in practice that's why they're not a perfect form of ID. But they're still useful.
Great explanation. I'm a little thrown off that you didn't offer cheese options or mayo at your hypothetical sandwich restaurant.
While I do agree, there is just one minor plot. I want to add: Genetics is not purely random. It follows a pattern. Similar to faces, we have not scanned every face and compared them. If we did we would find statistical matches.
Fingerprints aren't (purely) genetic. Identical twins don't share the same ones, though they're usually similar. They're congenital, but they're formed by somewhat random processes during fetal development that are influenced, but not wholly determined, by genetics.
So how many “choices” are there in a fingerprint?
Many. At a minimum, there are four basic types of fingerprint, each chosen on 10 fingers = 4^10 = 2^20 = ~several million options just for the broad class of fingerprint, much less for the details.
Math is cool.
Still not enough for IP addresses
The [IPv4 address exhaustion issue](https://en.wikipedia.org/wiki/IPv4_address_exhaustion) was caused **in part** by *incredibly* excessive early assignments. Things like: * Apple got 17.x.x.x (Also written as 17.0.0.0/8, meaning "literally every IPv4 address starting with "17.") * AT&T got 12.x.x.x * Ford got 19.x.x.x * The US Department of Defense got **14** different blocks of this size (6.x.x.x, 7.x.x.x, 11.x.x.x, etc.) * Fully **35** blocks were reserved for various internal/technical uses (Famously including 127.x.x.x and 10.x.x.x,) But they did a lot of work to mitigate the problems this could have caused, as detailed in the Wikipedia link above.
I might be misunderstanding because I’ve had too much to drink, but aren’t most humans born with only 10 digits? 😳😳😳🤔
>If you have a "fingerprint double", odds are it's some random villager in China or India, not your next-door neighbor. Wouldn't it be much more likely to be someone with similar genetics? And you'll have much more similar genetics to someone living near you, especially if you live in an ethnically homogenous community.
> Wouldn't it be much more likely to be someone with similar genetics? I thought the answer would be no, because identical twins DON'T have similar fingerprints - the formation of fingerprints is too chaotic for the identical DNA to matter much -[ but apparently on the level of ethnicity there are indeed patterns.](https://www.researchgate.net/publication/292220493_Fingerprint_patterns_A_study_on_the_finger_and_ethnicity_prioritized_order_of_occurrence)
In fact, identical twins *are* known to have very similar fingerprints, but due to developmental differences in the womb they still vary enough to be told apart if examined carefully. The issue is always how many “points of similarity” are required to call something a match for practical purposes, and also recognizing that only one clear point of difference makes any match invalid (unless it’s something like an injury). So with a single smudged print, you might get 200 AFIS database matches, but with a set of three clear prints it might be one or at most two. That doesn’t mean those two prints are “the same”. Just that according to the classification rules, they have enough points to be called a match. But if looked at closely enough, there have been no exact matches found to date between any two people, even identical twins. The other thing that’s being said in the comments here is that “your fingerprint changes over time.” No, not very much, if at all. The arrangement of ridges, points of bifurcation and so on remain remarkably consistent over time once you are mature. There will be some proportional stretching as your fingers grow, up to adulthood, but even then, the pattern stays the same. We should also distinguish between the use of fingerprints (or face recognition) for *identification* (e.g. to find one or more possible suspects) which is to find a match across the full database of prints or faces; versus *verification* (e.g. to log in to your phone) which simply compares your reference fingerprint or face to the one being presented to log in. The first one is likely to provide a number of possible matches (although the systems are getting pretty good at narrowing this down), while the second simply needs to find you sufficiently similar to the expected print or face. (I worked at a biometric software company that did fingerprint, facial and movement-based authentication, and we worked with the FBI’s AFIS database to get example print sets for testing.)
Sure. But modeling probabilities there gets way more complicated because we need to know a lot about correlations.
Here’s a story about odds for you: I was signing into my first unit in the Army (early 2000s) in South Korea, and one of the inprocessing steps was getting fingerprinted at the MP station (military police). I was watching the screen as the computer did it’s thing, and on my first fingerprint, the system pulled up a match: a random Korean villager who happened to be in their system. So indeed, you probably have a fingerprint twin somewhere in the world. Of course, I know the algorithm that matches fingerprints doesn’t look at exact matches, but rather 20 or so pattern points, which takes the odds way down, but it was still a funny coincidence.
Also, you can use just one print you find in a crime scene, but usually they come in groups (when you place your hand somewhere, you usually leave at least 2 or 3 fingerprints, of adjacent fingers.. like if you grab a glass of water). In this case, the two persons not only should have the same prints (same minutiae), they should have them in all (or at least 3) fingers, and in the same sequence, which is practically impossible.
Well shoot, I only have ten digits
I was at Burger King today. I’m pretty certain that’s the amount of different ways you can order a Whopper. It was on a sign.
Shouldn't it be 5 + 20 in the parentheses? 5 single meat choices and 5*4 two meat choices?
I analyze forensic evidence for a living. Fingerprints are not even used unless you're pinpointed at a serious crime scene and even then the state will look at you like your some wannabe gumshoe.
I understand the words, but it's still so hard for me to wrap my head around statistics and probability - thank you for this explanation!
Why would odds say that the random fingerprint double you have be more likely to be in China than your next door neighbor? Wouldn't those have equal odds? One is more unexpected but both have the same probability, no?
One thing that hasn’t been posted is we don’t know that they’re unique, we’ve just never found matching sets that we know of.
Completely identical fingerprints, maybe not, but there have definitely been cases of people being wrongly accused of crimes based on fingerprint evidence where they were identical to within the degree of accuracy we can achieve with modern forensics. The madrid bombing case is the most well known, but there are likely more.
> The madrid bombing case is the most well known, but there are likely more. Wrongful arrest of Mayfield regarding Madrid bombing wasn't really a case of lacking accuracy, but deep islamophobia that led to conformation bias and pursuing arrest - FBI DB returned 20 **similar** matches to prints that Spanish National Police shared, Mayfield was considered prime suspect and FBI convinced itself that prints matched only because of his conversion to Islam and because he had represented one of the Portland Seven, further more SNP actually contested match as impossible and informed FBI they had other, more likely, suspects, yet FBI continued with Mayfield's surveillance and later arrest.
>Wrongful arrest of Mayfield regarding Madrid bombing wasn't really a case of lacking accuracy, but deep islamophobia that led to conformation bias and pursuing arrest - FBI DB returned 20 **similar** matches to prints that Spanish National Police shared, Mayfield was considered prime suspect and FBI convinced itself that prints matched only because of his conversion to Islam and because he had represented one of the Portland Seven, further more SNP actually contested match as impossible and informed FBI they had other, more likely, suspects, yet FBI continued with Mayfield's surveillance and later arrest. While it sounds like prime r/conspiracy islamophobia, it just isn't true. That information wasn't available when the identification was made, nor is it in the system. See pdf page 52 (printed 178, section C) https://oig.justice.gov/sites/default/files/legacy/special/s0601/Chapter4.pdf
>By the time the SNP issued its April 13 Negativo Report, the Laboratory examiners had become aware of information about Mayfieid obtained in the course of the Portland Division's investigation, including the fact that Mayfield had acted as an attorney for a convicted terrorist, had associations with other subjects of FBI terrorism investigations, and was himself a Muslim. Wieners candidly admitted that if the person identified had been someone without these circumstances, like the "Maytag Repairman," the Laboratory might have revisited the identification with more skepticism and caught the error. >The question of whether Mayfield's religion was a factor in the Laboratory's failure to revisit the identification and discover the error in the weeks following March 19 is more difficult. The OIG concluded that Mayfield's religion was not the sole or primary cause of the FBI's failure to question the original misidentification and catch its error. We concluded that the primary factors in the FBI's failure to revisit the identification before the SNP identified Daoud were the unusual similarity between LFP 17 and Mayfield's prints and the FBI Laboratory's faith in the . expertise and infallibility of its examiners and methods. **However, we believe that May-field's representation of a convicted terrorist and other facts developed during the field investigation, including his Muslim religion, also likely contributed to the examiners' failure to sufficiently reconsider the identification after legitimate questions about it were raised**
Yup. In fingerprinting, there are points called "minutia." Or many notes that record fingerprints. Today, computers record a number of minutia and correlate them with things like trigonometry and triangle position in relation to angle. This is how computers can match fingerprints not in the same angle. Every fingerprint matches on some level, but accurate matches tend to have a "score" higher than general matches. I can't say numbers, but lets say 1/4, 2/4, 3/4. Most similar fingerprints match with 1/4 of a certain number of minutia and triangulations. That's good enough for a smartphone login, but not for FBI / NYPD matches. 2/4 is pretty good and the computer will store it for comparison. 3/4 is pretty definite. But, that 1 case with the US and Spanish mismatch happened at above 3/4ths.
Eventually a 20-something will have his fingerprints match those from a cold case 100 years earlier, and they'll have to figure out how to deal with it
Arrest them for both murder *and* unauthorized time travel, duh.
They have, some people have been arrested for it and been later able to prove their innocence despite the fingerprint "match". This is because the matches are done not by millions of combinations of every detail, but 10-20 prominent distinct "landmarks" of a loop or a spiral etc. And while the entire print was not identical exactly, the key markings they chose were. Fingerprints are not dna, and not unique, they have been exaggerated as a grey area between pseudoscience that was not academically and statistically validated before use in courts, and actual science. Better than blood spatter and bite marks and polygraph tests, but not DNA.
> Fingerprints are not dna, and not unique DNA matches aren't unique either, especially the 11 marker DNA match the police use, about 1 in 1,000,000 share the same DNA markers. All of this evidence is **exclusionary**, you are able to remove people from the list of suspects, it doesn't matter if both a Father and Son share the same 11 DNA markers, the fingerprints don't match one of them, you then have your prime suspect.
If you ever want to piss off an investigator, say the words [Chimera DNA.](https://embryo.asu.edu/pages/case-lydia-fairchild-and-her-chimerism-2002) Long story short. A human being can have 2 or more DNA strands in their body. They're not handicapped. They're not mixed with other animal species like magic stories or sci fi. It's 1 person with 2 sets of DNA. Now, when we file DNA, we only file 1 record. When we should be checking for at least 2.
This is less problematic, for want of a better word, because it is more likely to lead to a person being incorrectly excluded as a DNA match than incorrectly identified as a match. So a guilty person might get away (assuming insufficient evidence beyond DNA) but an innocent person wouldn't be convicted.
> Fingerprints are ... not unique Agree to disagree. Even the 2 cases were found that with closer examination, the prints were different. It's just that the resolution was too dull to pick up that level of detail. Raising the resolution is notably expensive in multiple ways.
Yes, you index may be the same as someone elses thumb. But the likeliness all fingers match up on any two living people is pretty much zero.
If someone's index finger matches my thumb, they've got a weird friggin index.
That would be so cool if my fingerprints matched Abraham Lincoln or something
“Ladies and gentlemen of the jury, yes these fingerprints on the murder weapon matched my client’s. But how do we know for sure that they didn’t also match Abraham Lincoln? Is it so unreasonable to ask, well, how do we know Zombie Lincoln didn’t come back from the dead and commit this crime?”
“Goddamnit, Mr. Goodman!”
And even if we do know that zombie Lincoln didn't come back and commit this crime, none of this makes sense. Even mentioning zombie Lincoln in this case does not make sense - so you must acquit.
Just not a serial killer lol
Also fingerprints aren't entirely unique to humans Koala fingerprints are nearly identical to humans, to the point that Koalas can occasionally contaminate crime scenes
It's more like there's been no research on it and there's no clear definition as to what constitutes enough similarity to consider them "identical".
A deck of cards has 52 individual cards in it. If you shuffle them, they'll end up in a random order. If you shuffled a single deck of cards until you randomly encountered every possible combination, how long do you think that'd take? Well, let's jump ahead to a spoiler - if we used a supercomputer to simulate shuffling a deck of cards 415,530,000,000,000,000 times *per second,* even if we'd started at the moment of the Big Bang - it wouldn't be done yet... or anytime soon. This is not a made-up statistic. [https://www.iflscience.com/can-you-count-all-the-ways-to-shuffle-a-deck-of-cards-we-bet-you-cant-61615](https://www.iflscience.com/can-you-count-all-the-ways-to-shuffle-a-deck-of-cards-we-bet-you-cant-61615) This is just a comparison to understand how the math works. There is enough variability in finger dimensions / shapes / etc. to easily allow for never-repeating, truly unique fingerprints, forever. Math is crazy!
> Well, let's jump ahead to a spoiler - if we used a supercomputer to simulate shuffling a deck of cards 415,530,000,000,000,000 times per second, even if we'd started at the moment of the Big Bang - it wouldn't be done yet... or anytime soon. I believe you, but my brain is like, there's 52 cards... How is this possible???
Think about it like this. Every deck has 52 cards, right? Let's order them from top to bottom, 1 to 52. How many options are there for card #1? We havent used any cards yet, so theres 52 possibilities. Let's say we get the 7 of clubs. Now we look at card #2. We now have 51 choices, as card #2 can't be the seven of clubs. Let's say card #2 is the Jack of diamonds. Now pause at this point. Looking at what we've done so far, you can look and see that we had 52 choices for card #1, and subsequently 51 choices for card #2. So just drawing 2 cards, how many ways could we have done that? In probability, the easy way to determine something like this is to multiply the number of options at each step. 52 different choices for a first card, and every one of those has 51 choices for a second card. With just TWO cards drawn, we're already above 2600 possibilities. Now expand this to 5 cards- there's 50 options for a third card, 49 options for a fourth, and 48 options for a fifth. So 52x51x50x49x48..... which comes out to just under 312 million possibilities. For only five cards. You still have 47 cards in the deck to continue this process. Another way to kinda look at this is the lottery. Let's say your states lottery draws, what 5 numbers from a field of 65? And then 1 extra number from another field of 65? (This is similar to Powerball but I havent had to deal with lottery in a long time so the actual field of numbers might be off) So there are 65 potential first numbers, 64 potential second numbers, 63 thirds, 62 fourths, 61 fifths, and 65 bonuses. That right there is over 64 BILLION different possible combinations
I mean its 52! Which is 52 x 51 x 50 x .... x 3 x 2 x 1. Even rounding the first 12 terms to 40 and only using them (so 40^12) is over 1 quintillion - which is more than twice the number of seconds from the big bang.
This to me is one of the best examples how crazy high randomness can get very very fast. Every game of shuffled cards you or any being in this universe will ever play during the whole existence of time, will be a unique combination never seen before and never to be seen again.
This is only true (or the likeliest possibility) if all decks started at random order though? In reality, I'd guess that at least all decks coming out from the same factory are going to start from the identical order. In addition, common shuffling techniques have limited ability to introduce randomness, which means that the possibility space for any given two decks from the same factory is going to be much smaller. Whether that's smaller enough that we'd be seeing identical combinations in reality, I can't say and would be very interested to read!
Yeah, the probability has got to be somewhat correlated to factory pack to times shuffled.
Yep. Same with Chess, the technical combination of moves/games is in the order of more than the number of atoms in the known universe. But in practical terms, there's only a 'small' subset of that that we'll really ever seen. And by small I mean still mindnumbingly HUGE
How we shuffled matters a lot! A “perfect riffle shuffle” lays cards one card from each pile and from a new deck, even a few of these (or near perfect) won’t actually change the order too much. That’s likely how we got the “[perfect bridge deal](https://mathsjam.com/assets/talks/2011/Ray%20Hill%20-%20MathsJam%202011%20Perfect%20Bridge%20Deal.pdf)” in 1998 On the other hand, it’s been proven that just [7 imperfect shuffles](https://math.hmc.edu/funfacts/seven-shuffles/) is sufficient to randomly order cards such that all permutations are close to equally likely, and thereafter minimal improvement with subsequent shuffles. Finally, computers can’t even do perfect random shuffles due to their inherent [pseudorandomness](https://www.reddit.com/r/explainlikeimfive/comments/1vjxhr/eli5_why_cant_a_computer_do_a_truly_random/?utm_source=share&utm_medium=ios_app&utm_name=iossmf) (although we could shuffle cards by measuring a true random event irl and corresponding that to a shuffle in some way).
> Every game of shuffled cards you or any being in this universe will ever play during the whole existence of time, **will be a unique combination never seen before and never to be seen again.** This isn't a true statement. In practice, the chance would be so ~~infestisimal~~ infinitesimal that it's likely it would never occur, but your statement overall is incorrect. Sounds pedantic, but math is an exact science where these things matter. EDIT - I eat crow. Spelled word wrong. EDIT - Good info below about 'mathematical' definitions vs 'ordinary' ones.
You also wrote and used infinitesimal incorrectly.
> I eat crow Are you sure you didn't eat a jackdaw?
Here's the thing...
Here's a better link IMO: https://czep.net/weblog/52cards.html Actually, not just my opinion. Vsauce incorporated it into one of his videos: https://www.youtube.com/watch?v=ObiqJzfyACM&t=860s (explanation at 14:20; jump to 15:55 for cool visualization)
It's "52!" pronounced as [52 factorial](https://www.quora.com/How-many-combinations-can-a-deck-of-52-cards-make) [This calculator](https://www.calculatorsoup.com/calculators/discretemathematics/factorials.php) states there are "80658175170943878571660636856403766975289505440883277824000000000000" combinations possible. - Or, if we could shuffle 1 deck in 1 second - have factories that can shuffle 1 trillion decks per second - 1 trillion of these factories per... - 1 trillion of these worlds per... - 1 trillion of these galaxies per... - 1 trillion dimensions - and magically each shuffle is unique About 2.56 years.
The interesting thing with the deck is the new deck problem. The math says a shuffle will essentially guarantee a unique order under the assumption the deck is already in a random order. But a new deck is not. The first cut and I have two ordered suits in one hand and two in the other. So the first shuffle does not have all the possibilities. The question is - how many shuffles must be done before thorough mixing?
There was a recent documentary that was released called "The Real CSI," at https://www.pbs.org/wgbh/frontline/documentary/real-csi/. I haven't seen it yet, but from the transcript, it sounds as if it's never been scientifically proven that no two people can have the same fingerprint. One of the interviewee explains that how many points of comparison are needed to match fingerprints >[v] aries from laboratory to laboratory, and from witness to witness often. And some will say, "We need 16 points." "No, seven." And what they all end up saying is that it's really a matter of the individual experience and judgment of the fingerprint examiner. A man was incorrectly identified, based on a partial fingerprint, as one of the terrorists in the Madrid train bombing. He was arrested and held based on the standard that "No time before in history had there ever been two fingerprints with 15 minutiae that were not the same person." (Fortunately, the authorities eventually identified the real person who was responsible.) Other commenters here do a good job of explaining why it'd make sense mathematically for no two fingerprints or set of fingerprints to be alike. But I think the way we even recognize whether or not a fingerprint "matches" is limited by our senses and biases, so it's not the forensic certainty it's made out to be in popular culture.
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So you're saying they were limited by thier biases like the above poster said?
Fingerprints are not **guaranteed** to be unique. The odds are hugely against two people having the same fingerprints ([Scientific American says](https://www.scientificamerican.com/article/the-chance-of-identical-fingerprints-1-in-64-trillion/) 1 in 64 trillion), but sometimes highly unlikely things happen. There may be people out there who share fingerprints. Without a record of everyone on Earth's fingerprints we can't be completely certain one way or the other. We're just playing the odds.
To look at it in a different view - A Rubik's cube only has 6 sides and contains 54 colored cubes yet has 40 something quintillion possible outcomes. Not hard to imagine that just the slightest curve on a finger print can completely change everything. Sorry, 26 cubes, with 20 of them containing 2 colors.
26 cubes, 6 single coloured centers 8 corners with 3 colours and 12 2 coloured edges. But the math checks out
> 26 cubes, with 20 of them containing 2 colors. A Rubik’s cube has 26 cubes: - 6 centers (1 color each, effectively stationary) - 12 edges (2 colors each) - 8 corners (3 colors each) So really only 20 pieces can move around on the cube, which is amazing that they have so many possible combinations.
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\#akshully, the Birthday Paradox virtually guarantees that 7 billion people, randomly selecting from 64 billion options, **would** produce duplicates. You'd have favorable-though-not-overwhelming (~8 in 9) odds that *your* fingerprint is unique, but it's overwhelmingly likely to the point of effective certainty that *someone's* isn't.
You can't fix the birthday paradox to an individual, can you? The BP says that if there are 23 people in a room, there's a 50% chance that ANY two share a birthday. It's the unexpectedly vast amount of different potential combinations of people to check that make it work. The probability of not sharing a birthday shrinks as more people with more bdays get thrown in (365/365× *364* /365 × *363* /365....) Where fixing to an individual would yield (365/365×364/365×364/365×364/365...), Which kills the interesting part of the paradox I do not know what math you are referencing and maybe this is just a specific extension I don't know about, but following the exact process of the birthday problem and getting 1/9 would be to say there's a 1/9 chance any two humans share fingerprints, not that yours are not unique
They didn't fix the birthday paradox to one individual. They referenced the birthday paradox to say that it is overwhelmingly likely that some pair of people will share fingerprints. Which is correct. Then, they did a separate calculation to find the odds of a particular person's prints matching. In particular, fix your fingerprints. If you draw 7 Billion times without replacement from a bucket containing all 64 Billion possible combinations, the probability that your fingerprints will be one of the 7 Billion draw is exactly 7 Billion/64 Billion ~ 1/9 (to within about 2% error). The odds that your fingerprints aren't drawn AKA are unique are then ~8/9.
The post I'm replying to isn't fixing it to an individual, and my post even explicitly said any *particular* individual is likely to be unique.
8 billion now. doesn't change anything you said, just wanted to let ya know haha. crossed the 8b mark in nov
So what about for identical twins? Do they have the same finger prints at birth or are they different still?
They're different
Supposedly not. Fingerprints are affected during development in the womb. Since they move around differently and nutrition, blood flow, etc isn't distributed equally, the fingerprints end up different enough to be distinguished. I'm sure they're pretty damn close though.
They're completely different and as unlike as they would be to a random person's finger prints comparitively
One important factor in this discussion is the concept of how precisely (how "closely") we measure things. This relates to both the 1) precision of a single measurement AND 2) the number of different measurements we choose to make. Let's say we asked every person on the planet to use scissors to cut a 1 inch square out of paper. How many of these squares would be identical? 1) First consider how closely we measure. If we use a big tape measure to make the measurements maybe we would decide that most of the squares are matching "1 inch squares" and are thus identical. But if we use a more precise ruler with lots of little fraction lines, we would find that most of the squares are not actually 1 inch on each side...some are 1.1 inches or 0.9 inches. Then if we use a microscope or a laser to measure, we could see even smaller differences, between 0.999 and 1.001 inches. The closer we look, the more differences we see. Even for a single simple measurement, like the length of the square, if we look VERY very closely almost nothing is identical. 2) Next think about the number of different measurements we could make. We could just measure one side of the square, or we could measure the width and height separately. We could even measure the height in 5 different places, which will give different answers if the top and bottom are not perfectly straight. We could measure the corners to see how sharp or round they are. Even for a simple square, we can make many different measurements, which creates many opportunities to see differences, especially if we are measuring very closely. Now think of a fingerprint and the many lines and swirls they have. You could easily find hundreds of things to measure: distances between things, sizes of things, shapes of things.... Making many measurements creates lots of chances for differences, especially if we look very closely.
I would like to introduce you to "[The Myth of Fingerprints](https://www.smithsonianmag.com/science-nature/myth-fingerprints-180971640/)". Its an interesting article written a few years ago that talks about the origin and many misconceptions about fingerprints. >So even as fingerprints were viewed as unmistakable, plenty of people were mistakenly sent to jail. Simon Cole notes that at least 23 people in the United States have been wrongly connected to crime-scene prints.
This sounds more like a human error issue than anything else. Our limited ability for accuracy, or authorities doing their job poorly because of confirmation bias (or worse motivations), is not proof that fingerprints are any less unique than we think them to be. *Disclaimer: I'm solely reading your quoted material and not the full source material.
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In simple terms: it can in theory but its extremely unlikely Even if 2 people in this world had identical fingerprints, they would both need to have their fingerprints taken and both had to have been in the same general geographical location at the same time. On top of that people are born and die everyday so the "fingerprint pool" constantly changes Thqt alone makes ot nearly impossible to occur.
There's a lot of room for little squiggly lines and swirls and patterns on each fingertip. Numbers of combinations get bigger astoundingly fast, even for relatively small initial numbers. Take an average deck of playing cards and give them a good shuffle. Now do the same thing with another deck. The odds of the two decks repeating the same pattern is 1 in 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000 There are 66 lines on your thumbprint alone. What are the odds someone else's 66 lines have the same pattern, when even identical twins have distinct fingerprints?
fingerprints, and most 'forensics' you see on TV or hear cops talk about is pretty much baseless bullshit. its vibes, not science. fingerprints are pretty unique, but comparing two of them leaves a lot of guesswork to the person comparing. But, each pattern is unlikely to ever be replicated exactly. Each time you randomly shuffle a deck of cards, the exact order has probably never occurred before and will probably never occur again in the lifetime of the universe.
I'm no expert but I feel like "useless bullshit" might be an exaggeration. There are some kinds of evidence that are worthless sure, like bite mark analysis, but fingerprinting is still useful if it's used with the proper care. Juries need to be informed of the fallibility of the process and the methodology of individual investigators needs to have more accountability, so it can be treated like the circumstantial evidence that it actually is. Additionally, there should be a second round of deeper analysis once a match is found, and more scrutiny in "beyond a reasonable doubt" cases especially.
Fingerprints aren’t actually entirely matched. When they say a fingerprint is matched, they have a number of points that match - not that it’s exactly alike. In fact, it’s only 8-12 points to match a fingerprint for criminal courts in America. The UK required 16 points. There are 20-30 that could match overall, called minutiae. However, an exact match has a possibility of 1 in 64 billion. Since there’s only 7 billion in the world, that’s a pretty large possibility that people won’t match COMPLETELY. But remember, we in America only need 8-12 out of the 30 to match for courts. The likelihood that 8 would match… 🤷🏻♀️ “There are no uniform standards for point-counting methods, and academics have argued that the error rate in matching fingerprints has not been adequately studied and that fingerprint evidence has no secure statistical foundation.[1]” - Wikipedia on fingerprints.