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Age Verification Laws: A Backdoor to Surveillance

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Re: Age Verification Laws: A Backdoor to Surveillance

#461

Post by devilbunny »

genewitch wrote: post #289
devilbunny wrote: post #139

Earlier quoted context omitted.

Yeah, the whole “we have to scan your driver’s license” which has my name, address, etc., encoded is way more than I want to share. I am mostly bald and even my beard is gray. There is no plausible situation where you think I might be under 21.

I've been gray for over a decade and get carded every time, because my state tries to enforce age restrictions. Minors don't seem to have much of a problem, though?

Nor would you if you sought the slummiest stores and gave some old wino $10 to go buy it for you.

Re: Age Verification Laws: A Backdoor to Surveillance

#462

Post by tzs »

hellojesus wrote: post #445
tzs wrote: post #331

Earlier quoted context omitted.

The party that you must disclose your identity to doesn’t necessarily need to see the credential you will present to the party you wish to demonstrate your age to. A blind signature could be used to have the ID checking party sign the credential without seeing it.

But can't the id checking party share info with the identity verification party to connect the dots?

Let W be a website that wants you to give evidence you are an adult.

Let C be an age check service.

A first stab at this would be something like this:

  1. W gives you a token T
  2. You show T and proof of identity/age to C
  3. C signs T
  4. You return the signed T to W
  5. W checks the signature and sees it is from C
The problem with that is what you noted. W and C could get together and then W could learn your full identity and C could learn that you use W.

C had to see the token to sign it, so at that point C and W both know T, and so that enables that matching up.

A blind signature addresses that by allowing C to sign with C needing to receive a copy of the token.

The way a blind signature works is that when you get the token, T, from W you apply a transformation to it which produces T'. It is T' that you send to C to sign for you. That gives you T' and a signature for T'. The signature algorithm and the blinding transformation are chosen so that they have this property:

• Given a document D, a blinded document D' produced by applying a blinding transformation do D, and a signature S' of the blinded document D', if you know the blinding transformation you can compute from D' and S' a signature S for D that will verify with the same key that produced S'.

The blinding transformation involves a random number that you pick. Even if C and W get together and compare lists of tokens they have seen they won't see any matches because W only saw unblinded tokens and C only saw blinded tokens and without knowing the random number used for that particular blinding they can't tell which unblinded token matches which blinded token.

They might try to match based on timing. If there isn't enough volume of people verifying they might be able to figure something out so care would definitely be needed especially at the start.

Re: Age Verification Laws: A Backdoor to Surveillance

#463

Post by AnthonyMouse »

tzs wrote: post #462
hellojesus wrote: post #445

Earlier quoted context omitted.

But can't the id checking party share info with the identity verification party to connect the dots?

Let W be a website that wants you to give evidence you are an adult. Let C be an age check service. A first stab at this would be something like this: 1. W gives you a token T 2. You show T and proof of identity/age to C 3. C signs T 4. You return the signed T to W 5. W checks the signature and sees it is from C The problem with that is what you noted. W and C could get together and then W could learn your full ident…

> They might try to match based on timing. If there isn't enough volume of people verifying they might be able to figure something out so care would definitely be needed especially at the start.

The timing attack is worse than that.

Suppose Bob has a pseudonymous account with the service. So he signs into his account, NotBob99, which is not supposed to be associated with Bob. Or even just uses a device with the same cookie or device fingerprint. On a dozen separate occasions.

Is he unmasked the first time? Maybe not, there could have been thousands of people requesting a signature at that time, although you have immediately narrowed it down by 99.999% from hundreds of millions. Is he unmasked the second time? Pretty good chance of that, because you can exclude anyone who didn't request a signature the first time. Even if it isn't fully unique yet, the number of candidates can now be counted on one hand. Has he been unmasked by the twelfth time? Almost certainly.

It's also not clear what the fancy cryptography is supposed to be buying you over the alternative. If you use blinded signatures, you have a timing attack, but Bob can still share the signatures unless the timing attack is being actively exploited, which it obviously isn't supposed to be as if it was it would only prove the signature scheme ineffective.

Now suppose you just have secret "is over 18" and "is over 21" passwords, changed on the same interval as the signatures would expire. The passwords aren't unique, everyone in the eligible age group gets the same one (and services that are 18+ request the 18+ password even from people over 21), so you can't correlate them with an individual and each person only has to request the password once per change interval (e.g. 30 days) rather than once per use. What advantage do blinded signatures have over this?

Re: Age Verification Laws: A Backdoor to Surveillance

#464

Post by AnthonyMouse »

LorenPechtel wrote: post #414
AnthonyMouse wrote: post #168

Earlier quoted context omitted.

> It would absolutely be possible to implement that stuff in a fully privacy-preserving way, with nothing but basic cryptography, and the government could absolutely enforce that implementation. There are ways to do this which are less bad , but there is no way to do it "in a fully privacy-preserving way" without also making it fully ineffective, because if there is no way to prove who someone is then there is no way…

I don't see how it could be fully privacy preserving. It's the government trying to get the information, the repository is not secure! However, you could come close. Sell a simple USB device that generates codes. It can only be purchased in person by showing ID--but the ID is not recorded. Down the road it can only be traced to the device, not to the purchaser. But you would no doubt see them for sale by unscrupulous…

Why does everyone want to make it complicated?

You don't need hardware. You don't need cryptography. You show your ID and you get a password. The password is the same for everyone so it can't be correlated with anyone.

Will people share the password? Of course, and they would also share the signatures or devices or whatever else, because you can't prevent that while also preserving privacy.

Re: Age Verification Laws: A Backdoor to Surveillance

#465

Post by hellojesus »

tzs wrote: post #462
hellojesus wrote: post #445

Earlier quoted context omitted.

But can't the id checking party share info with the identity verification party to connect the dots?

Let W be a website that wants you to give evidence you are an adult. Let C be an age check service. A first stab at this would be something like this: 1. W gives you a token T 2. You show T and proof of identity/age to C 3. C signs T 4. You return the signed T to W 5. W checks the signature and sees it is from C The problem with that is what you noted. W and C could get together and then W could learn your full ident…

Thanks so much for that explanation. You even addressed timing attacks, which is what I was about to ask as a follow-up until I scrolled down and saw the final paragraph. I appreciate the write up!

Re: Age Verification Laws: A Backdoor to Surveillance

#466

Post by tremon »

hellojesus wrote: post #447
djsjajah wrote: post #175

Earlier quoted context omitted.

No. Kids would need to memorize the private key of their parents id card.

What stops me, a random person, from publishing my private key online for anyone to use?

Common risk awareness, one would hope. What's to stop a random criminal from using that private key to take out a big loan in your name?

Re: Age Verification Laws: A Backdoor to Surveillance

#467

Post by hellojesus »

tremon wrote: post #466
hellojesus wrote: post #447

Earlier quoted context omitted.

What stops me, a random person, from publishing my private key online for anyone to use?

Common risk awareness, one would hope. What's to stop a random criminal from using that private key to take out a big loan in your name?

I would assume that my private key for pricing my identity to random websites is different than that used to make financial transactions. Why would I ever elect to keep it the same?

Re: Age Verification Laws: A Backdoor to Surveillance

#468

Post by kerkeslager »

ty6853 wrote: post #450
kerkeslager wrote: post #443

Earlier quoted context omitted.

I don't know why I'd form an opinion on whether he's prejudiced--I'm not particularly interested in classifying people based on arbitrary divisions, especially when they're pendantic dictionary definitions that include archaic meanings of the word. I'm more interested in discussing people's beliefs and behaviors. Two situations have been mentioned in this thread: 1) coming across two men kissing in public, and 2) you…

> by questioning the beliefs that cause you to feel what you're feeling I think one oversight is that you presuppose this. My beliefs in this case counter my feelings. I have nothing but warm regards, in belief, for dudes that want to kiss dudes. And I've gone to gay events, pride, gay nightclubs, made gay friends, worked with gay peopke, done all the things to normalize it in my mind and the negative feeling from wa…

Half the ancestor comments have been flagged out of existence, so I have no way of reminding myself of what was said, but my memory was that you said something which pretty much no gay person needs to be hearing. There's not some sort of accounting where you go to a gay event and then you get to make X number of shitty comments about gay people online. This is basically the "I have a black friend so I can't be rascist" thing.

Your feelings may be acceptable, but it's not necessarily acceptable to share every acceptable feeling you have with everyone. There are plenty of people I meet on a day to day basis that I'm not attracted to, of many genders and sexualities, and that's fine. But I've never once felt it necessary to tell one of those people that I'm not attracted to them, and doing so would be pretty rude and inconsiderate. If my memory of the flagged comments is correct, that's basically what you did. Sure, your feelings are fine, you don't really control those. But did you have to share them on the internet where they might hurt people who read them?

I don't want to blow this out of proportion. In the grand scheme of things, this isn't that bad and I don't think you need to be like ostracized from society or barred from holding positions of power or something. People make mistakes and this isn't a big one. But I do think it is a mistake.

Re: Age Verification Laws: A Backdoor to Surveillance

#469

Post by Nickolya »

mjevans wrote: post #71

The Internet should be Unrated and thus Adults Only by default. Just like public spaces. (Would you allow an 8 year old to wander New York City unattended? Arguments can be made for more controlled spaces but...) Have a website and want the chance for kids to see it? Advertise in the headers that it's moderated and intended to be a given rating. Various indexers can pick that up. Complaints can be forward to relevant…

This perspective aligns with the ongoing debate about balancing open access to information with the need to protect younger audiences from inappropriate content. Implementing such a model would require robust tools to manage and filter content effectively. In this context, services like NodeMaven can play a pivotal role by offering advanced proxy solutions that allow users to customize their internet experience, ensuring that content is both accessible and appropriate based on individual or organizational preferences. I can send you the link, it helped me a lot while writing my thesis https://nodemaven.com/.
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