[gruez]

>Modern versions of this technique allow one to associate metadata (like a proof of age exceeding a threshold) in such a way that the verifier can't even correlate repeated requests across users.

If it's unlinkable, what's preventing someone from setting up a site that hands out anonymous tokens for anyone to use?

[discodachshund]

Using cryptographic signatures from approved signers, like a government

[gruez]

No, I'm meant me, using my 18+ ID to generate a bunch of tokens that can't be linked back to me, and then giving it to random < 18 year olds for the lulz.

[quotemstr]

There are multiple approaches. One, which the Europeans use, hardware-locks the token. Each age attestation is unlinkable, but the cryptographic credentials you need to make the attestation aren't portable. Of course, this model requires a big statist apparatus that does implementation certification, but it does achieve the narrow goal of unlinkable, privacy-preserving age attestation that doesn't instantly decay to mass copying.

Other approaches are possible. I'm particularly keen on ones that treat attestations as anonymous digital currency and use cryptographic penalties like slashing to discourage copying post-hoc instead of relying on EU-style implementation certification.

There's a huge literature on the subject I don't want to reproduce here. The point is that yes, we do have the technology to do attestation without sacrificing privacy, which makes all the calls for non-privacy-preserving attestation awfully curious.

[Aurornis]

> One, which the Europeans use, hardware-locks the token.

I'm surprised anyone considers this viable.

It would limit access to those sites to a limited set of acceptable devices and operating systems.

I couldn't use my laptop, desktop, or a jailbroken phone.

[Magnusmaster]

Exactly. And the funny thing is that the EU Age Verification App seems to be vulnerable to relay attacks anyway.

[Terr_]

> as anonymous digital currency and use cryptographic penalties like slashing

Or make it so that tokens cannot be tested except by spending/burning them, which would significantly reduce (but not eliminate) a black market because it would be hard for any buyers to trust any sellers.

The best outcome here is going to rest on getting people to agree that "good enough" is the best outcome. We want a system that gets the broad social results (e.g. less brain-rot in the kids) without being so impossibly strict and overbuilt that it leads to an even-worse problem (e.g. authoritarian hellhole tools.)

[jszymborski]

I'm not familiar with this, but what your describing sounds similar to the hardware DRM keys used for protecting 4K streams from being downloaded from Netflix.

If so, this stuff is already broken, and imagine it would be pretty simple to apply the same principles here.

I'm probably wrong on this though I'm out of my depth

[paulddraper]

The verification service would tie the token to the IP address/geolocation. It would also throttle the number of identifications, or expire old ones.

Yes, that can eventually be worked around, but not really that different than doing the verification today on someone else's device.

[Aurornis]

> The verification service would tie the token to the IP address

So I'm constantly grabbing new tokens from the government every time I go from work WiFi to my cellular internet to the train WiFi and then home?

Sounds like a fantastic point for capturing more tracking data.

> /geolocation.

Which means I have to send my geolocation data to apps to confirm I can use my token?

Don't want that either.

> It would also throttle the number of identifications,

And if I move around too much in one day or change networks too often, I'm unable to log into anything until tomorrow?

[Nursie]

> So I'm constantly grabbing new tokens from the government every time ...

Every time you set up an account, would generally be the idea. So relatively infrequently.

[gruez]

>The verification service would tie the token to the IP address/geolocation

"Use this exact tor/vpn server"

>It would also throttle the number of identifications

So I can only wank off 5 times a day, or grant access to porn sites for 5 kids?

[worble]

What's to stop you, using your 18+ ID from buying crates of alcohol and giving it to random < 18 year olds for the lulz?

[Aurornis]

Because those <18 year olds will immediately flip and identify you to the cops to try to lighten their punishment.

The anonymous crypto token scheme does not have any trace-back mechanism like this at all. If there's no way to track those tokens back to you, why not sell them for $1 each on the internet to make some extra money?

[gruez]

For one, I have to do it in meatspace so it's easily traced back to me, whereas anonymous tokens can't be traced back to me by design.

[laughing_man]

The minute this scheme went into place, there would be sites based in one of the "stans" selling tokens for a couple bucks to whomever wanted to buy.

[Retr0id]

Yes, this breaks the whole scheme. Anyone promoting it as a solution is delusional. There's a triangle of "robust", "private", and "practical" and you can only pick two. This one omits robust. The various mitigations people might suggest in response will have to sacrifice one of the other dimensions.