126
Homomorphic encryption (zero knowledge cryptography) is a known solution to this problem.
https://crypto.stackexchange.com/questions/96232/zkp-prove-that-18-while-hiding-age
this post was submitted on 30 Nov 2024
126 points (99.2% liked)
Programming
17669 readers
234 users here now
Welcome to the main community in programming.dev! Feel free to post anything relating to programming here!
Cross posting is strongly encouraged in the instance. If you feel your post or another person's post makes sense in another community cross post into it.
Hope you enjoy the instance!
Rules
Rules
- Follow the programming.dev instance rules
- Keep content related to programming in some way
- If you're posting long videos try to add in some form of tldr for those who don't want to watch videos
Wormhole
Follow the wormhole through a path of communities [email protected]
founded 2 years ago
MODERATORS
Doesn’t this assume the issuing agency has all employees who are morally sound and not leaking data, unnoticed by an internally badly designed system, which is designed by people who are out of touch? Most things like this are designed that way, irregardless of country .
I’m sure one can make it watertight but it’s so hard and still depends in trusting people. The conversation here is about one thing of a larger system. There are probably a hundred moving parts in any bureaucracy.
This is the understanding ANYWHERE. How do we know there aren’t back doors in our OS’s? We literally have no clue. We do THE BEST WE CAN using the clues we have.
Yeah, these things quickly boil down to the trusting trust thing (see Ken Thompson's Turing award lecture). You can't trust any system until you've designed every bit from scratch.
You gotta put your trust somewhere, or you won't be able to implement jack.
load more comments
(1 replies)
I don’t know anything about cryptology; I have an imagination about how many things can go wrong hooking up parts and running them.
If it’s the law to make an age verification system then it will be made.
But I think one either has an age verification or privacy, but not both, in any country in the world.
I’m totally sure many of the discussions here about crypto are way above my head. But I’m equally sure while any one part will look fine in paper, the sum total will be used by an expanding government agency, crime, or both.
God I hate cryptography so much for making me feel stupid every time I read anything about it.
I want to feel smat!
I find it intimidating for sure. They say “never roll your own crypto” and I take those words to heart. Still, it would suck to have to hire someone and just trust their work. That person could be another Sam Bankman Fried or Do Kwan and you’d be party to their scam and you’d have no idea.
load more comments
(4 replies)
load more comments
(11 replies)
Frankly, the only sane option is an "Are you over the age of (whatever is necessary) and willing to view potentially disturbing adult content?" style confirmation.
Anything else is going to become problematic/abusive sooner or later.
Not a cryptographic expert by any means but maybe something like this would work. This'd be implemented in common places people shop: supermarkets for instance. You'd go up to customer service and show your ID for visual confirmation only; no records can be created. In return the service rep would give you a list of randomised GUIDs against which the only permissible record can be "has been taken". Each time you need to prove your age you'd feed in one of those GUIDs.
this is an actual answer which is therefore interesting
Sadly, this type of scheme suffers from: 1) repudiation, and 2) transferability. An ideal system would be non-repudiable, meaning that when a GUID is used, it is unmistakably an action that could only be undertaken by the age-verified person. But a GUID cannot guarantee that, since it's easy enough for an adult to start selling their valid GUIDs online to the highest bidder en-masse. And being a simple string, it can easily and confidentially be transferred to the buyer, so that no one but those two would know that the transaction actually took place, or which GUID was passed along.
As a general rule, when complex questions arise which might possibly be solved by encryption, it's fairly safe to assume that expert cryptographers have already looked at the problem and that no easy or obvious solution exists. That's not to say that cryptographers must never be questioned, but that the field is complicated enough that incomplete answers abound.
IMO, the other comments have it right: there does not exist a general solution to validate age without also compromising anonymity or revealing one's identity to someone. And that alone is already a privacy compromise.
You upload identity to a site and it gives you a date stamped token which confirms your age.
Then when that token is uploaded to an SM site, it verfies the identity of the giver with the site that gives the token. The identity is a hash generated by the token site and contained in both the token and a namespace at the token site, so only the token site knows the real identity. Once the token has been confirmed, the namespace is re-used.
So you can't really sell the token, because its linked back to the identity you uploaded to the token site. You need to be logged in to the token site.
To make sure we're all on the same page, this proposal involves creating an account with a service provider, then uploading some sort of preexisting, established proof-of-identity (eg passport data page), and then requesting a token against that account. The token is timestamped and non-fungible, so that when the token is presented to an age-restricted website, that website can query the service provider to verify that: 1) the token is still valid, 2) the person associated with the token is at least a certain age.
If I understood that correctly, what you're describing is an account service combined with an identity service, which could achieve the objectives of a proof-of-age service, but does not minimize privacy complications. And we already have account services of varying degrees and complexity: Google Accounts, OAuth, etc. Basically any service where you log-in, since the point of logging in is to associate to a account, although one person can have multiple accounts. Passing around tokens isn't strictly necessary since you can just ask the user to prove account ownership by signing into their Google Account, for example. An account service need not necessarily verify age, eg signing in to post a comment on a news article.
Compare this with an identity service like ID.me, which provide records on an individual; there cannot be multiple records for the same live person. This type of service is distinct from an account service, but some accounts are necessarily tied to a single identity, such as online banking. But apart from KYC regulations or filing one's taxes online, an identity service isn't required for most day to day activities, and any additional uses pose identify theft concerns.
Proof-of-age -- as I understand it from the Australian legislation -- does not necessarily demand an identity service be used to satisfy the law, but the question in this Lemmy thread is whether that's a distinction without a difference. We don't want to be checking identities if we don't have to, for privacy and identity theft reasons.
In short, can a person be uniquely, anonymously age-verified online? I suspect not. Your proposal might be reasonable for an identity service, but does not move us further towards a theoretical privacy-centric proof-of-age validation mechanism. If such a mechanism doesn't exist, then the Australian legislation would be mandating identity checks for subject websites, which then become targets for the holder of those identity records. This would be bad.
load more comments
(1 replies)
You can't.
Age verification is not compatible with any remotely acceptable version of the internet. It's an obscene privacy violation in all cases by definition.
Any implementation short of a webcam watching you while you use the site is less than trivial to bypass with someone else's ID while opening numerous massive tracking/security holes for no reason.
I seem to remember Leisure Suit Larry verified age using trivia questions that only older people would answer correctly. I know this because at 8 years old I guessed enough of them on my father's friends computer to play it.
oof, I'd fail trivia questions for my age group because I had a... complicated childhood. But it would probably be a problem for foreigners who didn't grow up the country. Imagine coming from Chile and having to know about Australian trivia from the 70s or something to sign up for a social media platform 😄
load more comments
(3 replies)
A joke answer, but with the kernel of truth - IRL age verification often requires a trusted verifier (working under threat of substantial penalty) but often doesn't require that verifier to maintain any documentation on individual verification actions
As in, you have to roll up to an "age verification bureau" and say "I'd like to sign up to $platform, please verify that I'm of legal age to use it and tell them so", then you buy a "token" that you can enter upon signing up? Am I understanding that correctly?
Sounds quite a lot like zero-knowledge proof
load more comments
(3 replies)
load more comments
(1 replies)
It can't. It requires invasion of privacy to verify information about the individual they don't have the right to access.
Digital age verification goes against privacy. Let's not delude ourselves into thinking it can.
If the governments would get their shit together, we could have something like age assertion with the eid chips in our IDs. Imagine that. The important thing is that website.com just asks the government "is this user an adult?" And the government replies "yes". No information besides the relevant one is provided, and it's through a trusted authority.
Yeah, not gonna happen, just like using the keys in my Personalausweis to send encrypted mail.
The system would have to be built so that the government can't connect the user to the website, as you don't want the government to build profiles on website usage by person. Though the bigger challenge here is trust - even a technically perfect system could be circumvented by the operators.
A good example for this were the COVID tracking apps. The approach was built so that as little information was leaked as possible.
Could have a system where a government site cryptographically signs a birth year plus random token provided by the site you want to use.
Step 1: access site
Step 2: site sends random token
Step 3: user's browser sends token plus user authentication information
Step 4: gov site replies with a string containing birth year, token, and signature
Step 5: send that string to the other site where it uses the government's public key to verify the signature, showing the birth year is attested by the government
No need to have any direct connection with the user's identity and the site or been the gov and site.
load more comments
(1 replies)
If I really had to, I would require everyone to whip out whatever assets of sexual maturity they happen to have, and let the computer analyze it and decide a maturity level.
I would also keep copies for blackmail purposes, because the world is a better place if we all mistrust this solution and anything remotely like it. It'll be in the legal fine print, which I'm confident no one will read.
Every answer (other than "trust the user to self identify") is at least remotely like mine, but I'm proposing we cut out the half-measures on the way.
To avoid personal consequences, the system I architect will probably wait on a dead-man-switch for me to die or be incarcerated.
Then it will publish everything it has ever seen, along with AI generated commentary. I'm confident that some of it will be hilarious, and I am hopeful that it will piss everyone off enough that we stop doing this kind of thing.
load more comments
(1 replies)
Sites are just going to ask people 'Are you over 16? (Y/N)'. Site is now legally covered, and that is all anyone cares about.
load more comments
(1 replies)
Its possible to implement something that hides your actual age from a website, but the tricky part is hiding what website you're visiting from an identity provider.
Let's walk through a wrong solution to get some fundamentals. If you're familiar with SSO login, a website makes a request token to login the user and makes claims (these request pieces of user information.) One could simply request "is the user older than 18?" And that hides the actual age and user identity.
The problem is how do you hide what website you're going to from the identity provider? In most SSO style logins, you need to know the web page to redirect back to the original site. Thus leaking information about websites you probably don't want to share.
The problem with proposals that focus on the crypto is that they actually have to be implemented using today's browser and HTTP standards to get people to use them.
load more comments
(7 replies)
My friend has worked with a government to create zero-knowledge proof from IDs. Turns out there's a lot of good software engineered to solve that problem.
The UX is still shit tho
Any open projects you could point to on the subject or articles about the government efforts? I would love to learn more on that!
https://github.com/openpassport-org/openpassport
I need to get back to Florent to ask him about his advances but this is the repo he worked on! Seems pretty exciting !
Choose the classic "are you 18 or older" dialog. KISS.
All I can think of are some variations of you trusting a service to validate your id and give you a token that just asserts your id has been validated.
But it's still not really privacy preserving because it relies on trusting both parties to not collaborate against your privacy. if at some point the id provider decides to start keeping records of what tokens were generated from your id, and the service provider tracking what was consumes with that token, then you can still put it all back together.
load more comments
(4 replies)
in blockchain tech, there's the concept of "zero knowledge proofs", where you can prove having certain information without revealing the info itself
Would be interesting to see a govt tackle setting up a trustless system like it required for cybersecurity best practices. I think it's a thorny issue without a trusted authority though.
What stops an ID for being posted publicly or shared en masse? So one ID can be used unlimited times - just share the key with minors for $1 at no risk to oneself since there's no knowledge of the 'transaction' being sent around. Better for individual privacy but that undermines the political impetus for wanting the verification. Usage would probably have to be monitored or capped, kind of defeating the advantage of the anonymous protocol (or accept that abuse is unenforceable).
load more comments
(2 replies)
Who has age authority? A state agency or service. Like the state issues an ID with age.
Preferable, we want the user to interact with a website, that website request age authentication, but not the website to talk to the government, but through the user.
Thus, something/somewhat like
- State agency issues a certificate to the user
- User assigns a password to encrypt the user certificate
- User connects to random website A
- Random website A creates an age verification request signed to only be resolveable by state agency but sends it to the user
- User sends the request to a state service with their user certificate for authentication
- State agency confirms-signs the response
- User passes the responds along to the random website A
There may be alternative, simpler, or less verbose/complicated alternatives. But I'm sure it would be possible, and I think it lays out how "double-blind"(?) could work.
The random website A does not know the identity or age of the user - only to the degree they requested to verify - and the state agency knows only of a request, not its origin or application - to the degree the request and user pass-along includes.
load more comments
(1 replies)
It cannot
Well Australia will probably so something privacy invading and fascist.
I guess if you want it to be somewhat private you could have some kind of hash or token generated from your identification information. I bet that would be fairly private
view more: next ›