5 ms·

> If we have to know that you're not a minor, then we also have to know who you are That is untrue

phyzome 10mo ago
Are you aware of any age verification systems that do not have this property? (This includes being robust against law enforcement action, legal or otherwise.)
- orblivion 10mo ago
  How about: https://blog.google/technology/safety-security/opening-up-zero-knowledge-proof-technology-to-promote-privacy-in-age-assurance/ https://blog.google/technology/safety-security/opening-up-ze...
- pksebben 10mo ago
  Like many mention in other comments on this post, it's possible to implement using ZKPs. There are likely other methods that would be effective without compromising privacy. None of them are part of the Age Verification discussion because kids are not the actual point of Age Verification. When I say "if we have to know you're not a kid, we have to know who you are" I'm not stating an actual truth, but the argument as it is playing out politically.
  - magicalhippo 10mo ago
    > None of them are part of the Age Verification discussion because kids are not the actual point of Age Verification. The EU age verification solution says implementations SHOULD implement[1] their ZKP protocol[2]. Not linking it to the user is stated as an explicit goal: Unlinkability: The goal of the solution is to prevent user profiling and tracking by avoiding linkable transactions. Initially, the solution will rely on batch issuance to protect users from colluding RPs. Zero-Knowledge Proof (ZKP) mechanisms will be considered to offer protection. More details are provided in Section 7. [1]: https://ageverification.dev/av-doc-technical-specification/docs/architecture-and-technical-specifications/#4-age-verification-solution-high-level-requirements https://ageverification.dev/av-doc-technical-specification/d... [2]: https://ageverification.dev/av-doc-technical-specification/docs/annexes/annex-B/annex-B-zkp/ https://ageverification.dev/av-doc-technical-specification/d...
    - crote 10mo ago
      If privacy is an explicit goal, why isn't it a MUST? Why even bother with the initial batch issuance phase? And what's stopping them from silently adopting a batch size of 1?
      - magicalhippo 10mo ago
        > Why even bother with the initial batch issuance phase? This is a solution that requires non-trivial interaction between many paries. It seems very reasonable to want to get the parties started on the implementation so they can iron out issues in the infrastructure they're building while they work on the details of the ZKP aspects.
    - mzajc 10mo ago
      Is there a good explanation of how ZKPs prevent attestation providers (which presumably know your identity) from linking an issued proof back to you if, for example, the website elects to store it? I can wrap my head around RSA and ECC and PKI, but I haven't managed to make sense of this yet. Assuming that's even a goal, of course. The cited paragraph mentions RPs (the websites, from what I understand), but makes no mention of attestation providers.
      - MatteoFrigo 10mo ago
        This is, of course, very technical, but here is how it works at a high level. In the non-ZKP presentation, the "holder" (phone) sends the credential to the relying party (website), and the RP executes some verification algorithm. In the ZK presentation, the holder executes the verification algorithm and sends to the RP a proof that the algorithm was executed correctly. The "proof" has this magical property that it reveals nothing other than the check passed. (You will have to take on faith that such proofs exist.) In particular, if the check was the predicate "I have a signature by ISSUER on HASH, and SHA256(DOCUMENT)==HASH, and DOCUMENT["age_gt_18"]=TRUE", anybody looking at the proof cannot infer ISSUER, HASH, DOCUMENT, or HASH, or nothing else really. "Cannot infer" means that the proof is some random object and all HASH, DOCUMENT, ISSUER, etc. that satisfy the predicate are equally likely, assuming that the randomness used in the proof is private to the holder. Moreover, a generating a proof uses fresh randomness each time, so given two proofs of the same statement, you still cannot tell whether they come from the same ISSUER, HASH, DOCUMENT, ...
  - knallfrosch 10mo ago
    > the argument as it is playing out politically. The law does not mandate identity, so your argument does not hold.
  - orblivion 10mo ago
    Okay but then if a ZKP solution is presented, that's calling their bluff. They now have one less excuse for surveillance. EDIT: Actually do one better - tell them that for 16+ websites, you're actually protecting teenagers by keeping them anonymous.
    - wcarss 10mo ago
      Yeah, getting into the car with the guy holding the gun doesn't become okay because you have a great argument you're waiting to use down the road. He's already got the gun out. We should have started arguing when he just said he had a gun, indoors, in the crowd. We shouldn't have quietly walked outside at his demand. But that all happened. Here we are now, at the car, and he's got the gun out, and he's saying "get in", and we're probably not going to win from here -- but pal, it's time to start arguing. Or better yet, fighting back hard. Because that car isn't going anywhere we want to be. We absolutely can not get in the car right now, and just plan to argue the point later. It doesn't matter how right the argument is at all.
  - joe_the_user 10mo ago
    The thing is that as far as I can tell, a ZKP of age involves a state or similar attestor to issue an ID/waller that can be querried for age without revealing identity. But attestor has to have certainty about the age of the person it issues IDs to. That raises obvious questions. What states are going to accept private attestors? What states are going accept other states as attestors? What state won't start using its issues ID/Wallet for any purpose it sees fit? This system seems likely to devolve national Internets only populated by those IDs. That can all happen with ZKPs not being broken. That is how states work.
  - phyzome 10mo ago
    Sure it's possible, but are there implementations in use that meet this criterion? Because if there aren't, then it matters substantially less whether they're possible.
  - miki123211 10mo ago
    The simplest possible such method? Single-use age verification codes, generated and validated by the government, sold on physical scratch cards with in-store verification of ID, piggybacking on the infrastructure we already use for selling alcohol and cigarettes. This would be far easier to implement for websites too. You'd just have a single, unauthenticated API endpoint which, given a code, tells you if the code is valid (and marks it as used). Integrating with such an API is about 1 day of work for a competent dev. Even open, non-profit platforms like Mastodon could easily implement such a mechanism. Scratch cards wouldn't have to be the only way of getting such codes. THe vast majority of people could just generate them in their banking app or whatever (which would still be far more privacy friendly than the current ID verification mechanisms).
    - deleted 10mo ago
      [deleted]
  - immibis 10mo ago
    You may be confusing the UKOSA (which is about surveillance) with the concept of age verification more generally.
- knallfrosch 10mo ago
  1) Large social media companies know you better than your friends. That has been known for 10 years and they're way better now: https://www.nytimes.com/2015/01/20/science/facebook-knows-you-better-than-anyone-else.html https://www.nytimes.com/2015/01/20/science/facebook-knows-yo... 2) Cigarette vending machines accept VISA cards and government IDs and they're offline. 3) A medium-sized social media network required photos (not scans) of GovIDs, where only year of birth and validity date need to visible. The rest could be blacked out physically. 4) You can guess users' age and only request solid proof only for those you are unsure about. The problem is that we technical users think of a one-size-fits-all technical approach that works, without a single fail, for all global users. That is bound to fail. It is only a law and you can break it big time or small time. Reddit's approach might proof way too weak, it'll be fined and given a year to improve. Others might leave the market. Others will be too strict and struggle to get users. Others might have weak enforcement and keep a low profile forever. Others will start small, below the radar and explode in popularity and then enforcement will have to improve. You can also request identity and then delete it. (Yes, some will fail to delete and get hacked.) Giving Facebook a free pass is stupid. They're selling your age cohort "10-11" within 0.0037ms for 0.$0003 to the highest bidder on their ad platform.
- delusional 10mo ago
  Cool trick to tie in the libertarian idea of protecting yourself from legally sanctioned government actions.
  - phyzome 10mo ago
    To make this more concrete: There are a lot of "legally sanctioned" government actions happening in the US right now that are pretty dubious. That includes digging up old laws and giving them spicy new interpretations that legal experts agree are an abuse of power and not in the intent of the original law. Some of these are getting batted down by judges, so right now the category of "legal" is especially vague. That's why I phrased it like that. But also, we see cops just straight up stalking people using government tools. So that's another reason to be concerned about "legal" government actions. Nothing to do with libertarianism.
- magicalhippo 10mo ago
  > Are you aware of any age verification systems that do not have this property? As I understand it, it's the goal of OpenID4VP[1][2]. Using it a site can request to know if the user is over 18 say, and the user can return proof of just that one claim, I'm over 18, without sharing identifying information. The new EU age verification solution[3] builds on this for example. [1]: https://openid.net/specs/openid-4-verifiable-presentations-1_0.html https://openid.net/specs/openid-4-verifiable-presentations-1... [2]: https://docs.walt.id/concepts/data-exchange-protocols/openid4vp https://docs.walt.id/concepts/data-exchange-protocols/openid... [3]: https://ageverification.dev/ https://ageverification.dev/
  - stvltvs 10mo ago
    Can't read the specs at the moment, but what prevents the age verification service and the age-gated website from coluding and de-anonymizing your porn use?
    - magicalhippo 10mo ago
      Haven't either had time to fully wrap my head around the details. At least in the EU solution they say there would be multiple attestation serivices the user could choose to use. So that would be technically better than nothing.
    - rcxdude 10mo ago
      With zero-knowledge-proofs the age verification could look like this: you go to whatever age verification service and get a certificate that says you're over the age of 18 (which you only need to do once or at least once per whatever expiry period). You then go to the age-gated website and they ask for proof. You generate (on your own device) a zero-knowledge proof that you have the certificate, but neither the website nor the verification service can determine which certificate it is, and in fact the verification service doesn't even know you've used the certificate.
- aidenn0 10mo ago
  GNU Taler has an age-verification extension.
- triceratops 10mo ago
  I have one: https://news.ycombinator.com/item?id=46223051 https://news.ycombinator.com/item?id=46223051

Are you aware of any age verification systems that do not have this property? (This includes being robust against law enforcement action, legal or otherwise.)

orblivion 10mo ago
How about: https://blog.google/technology/safety-security/opening-up-zero-knowledge-proof-technology-to-promote-privacy-in-age-assurance/ https://blog.google/technology/safety-security/opening-up-ze...
pksebben 10mo ago
Like many mention in other comments on this post, it's possible to implement using ZKPs. There are likely other methods that would be effective without compromising privacy. None of them are part of the Age Verification discussion because kids are not the actual point of Age Verification. When I say "if we have to know you're not a kid, we have to know who you are" I'm not stating an actual truth, but the argument as it is playing out politically.
- magicalhippo 10mo ago
  > None of them are part of the Age Verification discussion because kids are not the actual point of Age Verification. The EU age verification solution says implementations SHOULD implement[1] their ZKP protocol[2]. Not linking it to the user is stated as an explicit goal: Unlinkability: The goal of the solution is to prevent user profiling and tracking by avoiding linkable transactions. Initially, the solution will rely on batch issuance to protect users from colluding RPs. Zero-Knowledge Proof (ZKP) mechanisms will be considered to offer protection. More details are provided in Section 7. [1]: https://ageverification.dev/av-doc-technical-specification/docs/architecture-and-technical-specifications/#4-age-verification-solution-high-level-requirements https://ageverification.dev/av-doc-technical-specification/d... [2]: https://ageverification.dev/av-doc-technical-specification/docs/annexes/annex-B/annex-B-zkp/ https://ageverification.dev/av-doc-technical-specification/d...
  - crote 10mo ago
    If privacy is an explicit goal, why isn't it a MUST? Why even bother with the initial batch issuance phase? And what's stopping them from silently adopting a batch size of 1?
    - magicalhippo 10mo ago
      > Why even bother with the initial batch issuance phase? This is a solution that requires non-trivial interaction between many paries. It seems very reasonable to want to get the parties started on the implementation so they can iron out issues in the infrastructure they're building while they work on the details of the ZKP aspects.
  - mzajc 10mo ago
    Is there a good explanation of how ZKPs prevent attestation providers (which presumably know your identity) from linking an issued proof back to you if, for example, the website elects to store it? I can wrap my head around RSA and ECC and PKI, but I haven't managed to make sense of this yet. Assuming that's even a goal, of course. The cited paragraph mentions RPs (the websites, from what I understand), but makes no mention of attestation providers.
    - MatteoFrigo 10mo ago
      This is, of course, very technical, but here is how it works at a high level. In the non-ZKP presentation, the "holder" (phone) sends the credential to the relying party (website), and the RP executes some verification algorithm. In the ZK presentation, the holder executes the verification algorithm and sends to the RP a proof that the algorithm was executed correctly. The "proof" has this magical property that it reveals nothing other than the check passed. (You will have to take on faith that such proofs exist.) In particular, if the check was the predicate "I have a signature by ISSUER on HASH, and SHA256(DOCUMENT)==HASH, and DOCUMENT["age_gt_18"]=TRUE", anybody looking at the proof cannot infer ISSUER, HASH, DOCUMENT, or HASH, or nothing else really. "Cannot infer" means that the proof is some random object and all HASH, DOCUMENT, ISSUER, etc. that satisfy the predicate are equally likely, assuming that the randomness used in the proof is private to the holder. Moreover, a generating a proof uses fresh randomness each time, so given two proofs of the same statement, you still cannot tell whether they come from the same ISSUER, HASH, DOCUMENT, ...
- knallfrosch 10mo ago
  > the argument as it is playing out politically. The law does not mandate identity, so your argument does not hold.
- orblivion 10mo ago
  Okay but then if a ZKP solution is presented, that's calling their bluff. They now have one less excuse for surveillance. EDIT: Actually do one better - tell them that for 16+ websites, you're actually protecting teenagers by keeping them anonymous.
  - wcarss 10mo ago
    Yeah, getting into the car with the guy holding the gun doesn't become okay because you have a great argument you're waiting to use down the road. He's already got the gun out. We should have started arguing when he just said he had a gun, indoors, in the crowd. We shouldn't have quietly walked outside at his demand. But that all happened. Here we are now, at the car, and he's got the gun out, and he's saying "get in", and we're probably not going to win from here -- but pal, it's time to start arguing. Or better yet, fighting back hard. Because that car isn't going anywhere we want to be. We absolutely can not get in the car right now, and just plan to argue the point later. It doesn't matter how right the argument is at all.
- joe_the_user 10mo ago
  The thing is that as far as I can tell, a ZKP of age involves a state or similar attestor to issue an ID/waller that can be querried for age without revealing identity. But attestor has to have certainty about the age of the person it issues IDs to. That raises obvious questions. What states are going to accept private attestors? What states are going accept other states as attestors? What state won't start using its issues ID/Wallet for any purpose it sees fit? This system seems likely to devolve national Internets only populated by those IDs. That can all happen with ZKPs not being broken. That is how states work.
- phyzome 10mo ago
  Sure it's possible, but are there implementations in use that meet this criterion? Because if there aren't, then it matters substantially less whether they're possible.
- miki123211 10mo ago
  The simplest possible such method? Single-use age verification codes, generated and validated by the government, sold on physical scratch cards with in-store verification of ID, piggybacking on the infrastructure we already use for selling alcohol and cigarettes. This would be far easier to implement for websites too. You'd just have a single, unauthenticated API endpoint which, given a code, tells you if the code is valid (and marks it as used). Integrating with such an API is about 1 day of work for a competent dev. Even open, non-profit platforms like Mastodon could easily implement such a mechanism. Scratch cards wouldn't have to be the only way of getting such codes. THe vast majority of people could just generate them in their banking app or whatever (which would still be far more privacy friendly than the current ID verification mechanisms).
  - deleted 10mo ago
    [deleted]
- immibis 10mo ago
  You may be confusing the UKOSA (which is about surveillance) with the concept of age verification more generally.
knallfrosch 10mo ago
1) Large social media companies know you better than your friends. That has been known for 10 years and they're way better now: https://www.nytimes.com/2015/01/20/science/facebook-knows-you-better-than-anyone-else.html https://www.nytimes.com/2015/01/20/science/facebook-knows-yo... 2) Cigarette vending machines accept VISA cards and government IDs and they're offline. 3) A medium-sized social media network required photos (not scans) of GovIDs, where only year of birth and validity date need to visible. The rest could be blacked out physically. 4) You can guess users' age and only request solid proof only for those you are unsure about. The problem is that we technical users think of a one-size-fits-all technical approach that works, without a single fail, for all global users. That is bound to fail. It is only a law and you can break it big time or small time. Reddit's approach might proof way too weak, it'll be fined and given a year to improve. Others might leave the market. Others will be too strict and struggle to get users. Others might have weak enforcement and keep a low profile forever. Others will start small, below the radar and explode in popularity and then enforcement will have to improve. You can also request identity and then delete it. (Yes, some will fail to delete and get hacked.) Giving Facebook a free pass is stupid. They're selling your age cohort "10-11" within 0.0037ms for 0.$0003 to the highest bidder on their ad platform.
delusional 10mo ago
Cool trick to tie in the libertarian idea of protecting yourself from legally sanctioned government actions.
- phyzome 10mo ago
  To make this more concrete: There are a lot of "legally sanctioned" government actions happening in the US right now that are pretty dubious. That includes digging up old laws and giving them spicy new interpretations that legal experts agree are an abuse of power and not in the intent of the original law. Some of these are getting batted down by judges, so right now the category of "legal" is especially vague. That's why I phrased it like that. But also, we see cops just straight up stalking people using government tools. So that's another reason to be concerned about "legal" government actions. Nothing to do with libertarianism.
magicalhippo 10mo ago
> Are you aware of any age verification systems that do not have this property? As I understand it, it's the goal of OpenID4VP[1][2]. Using it a site can request to know if the user is over 18 say, and the user can return proof of just that one claim, I'm over 18, without sharing identifying information. The new EU age verification solution[3] builds on this for example. [1]: https://openid.net/specs/openid-4-verifiable-presentations-1_0.html https://openid.net/specs/openid-4-verifiable-presentations-1... [2]: https://docs.walt.id/concepts/data-exchange-protocols/openid4vp https://docs.walt.id/concepts/data-exchange-protocols/openid... [3]: https://ageverification.dev/ https://ageverification.dev/
- stvltvs 10mo ago
  Can't read the specs at the moment, but what prevents the age verification service and the age-gated website from coluding and de-anonymizing your porn use?
  - magicalhippo 10mo ago
    Haven't either had time to fully wrap my head around the details. At least in the EU solution they say there would be multiple attestation serivices the user could choose to use. So that would be technically better than nothing.
  - rcxdude 10mo ago
    With zero-knowledge-proofs the age verification could look like this: you go to whatever age verification service and get a certificate that says you're over the age of 18 (which you only need to do once or at least once per whatever expiry period). You then go to the age-gated website and they ask for proof. You generate (on your own device) a zero-knowledge proof that you have the certificate, but neither the website nor the verification service can determine which certificate it is, and in fact the verification service doesn't even know you've used the certificate.
aidenn0 10mo ago
GNU Taler has an age-verification extension.
triceratops 10mo ago
I have one: https://news.ycombinator.com/item?id=46223051 https://news.ycombinator.com/item?id=46223051