With many jurisdictions introducing age verification laws for various things on the internet, a lot of questions have come up about implementation and privacy. I haven't seen anyone come up with a real working example of how to implement it technically/cryptographically that don't have any major flaws.
Setting aside the ethics of age verification and whether or not it's a good idea - is it technically possible to accurately verify someone's age while respecting their privacy and if so how?
For an implementation to work, it should:
- Let the service know that the user is an adult by providing a verifiable proof of adulthood (eg. A proof that's signed by a trusted authority/government)
- Not let the service know any other information about the user besides what they already learn through http or TCP/IP
- Not let a government or age verification authority know whenever a user is accessing 18+ content
- Make it difficult or impossible for a child to fake a proof of adulthood, eg. By downloading an already verified anonymous signing key shared by an adult, etc.
- Be simple enough to implement that non-technical people can do it without difficulty and without purchasing bespoke hardware
- Ideally not requiring any long term storage of personal information by a government or verification authority that could be compromised in a data breach
I think the first two points are fairly simple (lots of possible implementations with zero-knowledge proofs and anonymous signing keys, credentials with partial disclosure, authenticating with a trusted age verification system, etc. etc.)
The rest of the points are the difficult ones. Some children will circumvent any system (eg. By getting an adult to log in for them) but a working system should deter most children and require more than a quick download or a web search for instructions on how to circumvent.
The last point might already be a lost cause depending on your government, so unfortunately it's probably not as important.
Great idea, let's get parents to raise their kids.
Now, how do we suddenly make them actually do that? Last I checked this idea has been around about as long as people have been around but it's still not happening.
Parenting matters, but it’s not the only layer of protection. We don’t rely solely on parents to keep kids from walking into bars or buying cigarettes, we have laws and systems to back them up. Why should the internet be different?
Let's not pretend that these laws actually do protect children..
There is always a way around something and if there's any population to figure it out, it's the ones with the most free time.
The difference between going to a bar and using the internet: Showing your ID at a bar doesn't mean it's stored on some server possibly ready to be stolen by hackers. It also doesn't automatically link all of your user data to your id (like it does right now) and make it easier to track your movements everywhere you go.
These laws help no one except the elite. They restrict us, limit access to information and eventually cause our data to be comprimised.
Bad parents exist, but does that mean we lockdown the most expansive knowledge base for everyone? I don't believe this will stop any children of bad parents from being exposed to horrible things online. Age gates don't stop that (because they either get bypassed or another site exposes even worse stuff without the age gate).
You see, if we tell parents that it's actually super important that they raise their kids, I'm sure they will do it. Just like if we tell everyone that a vaccine for a dangerous disease is a really good idea, everyone will just settle down and go get it.
How am I supposed to take care of my kids? My kid has got up at 3am and used his school device to do things I don't want. The thing wasn't supposed to be allow by the school but the bypass (web site not blocked) wasn't one the school will find out and block. Bypasses like that spread fast in schools.
My point is that we can't rely on parental oversight only because some plain won't... and in your case, even actively trying may fail (it's not your fault). And there's always going to be loopholes in every system. Clever kids will get by most verifications, and if they don't, that's likely to mean the verification gets too invasive to be worth it. The best, though not perfect system is to have parental oversight + impartial verification + platform responsibility. This will reduce but not eradicate the problem.
Problem is an OS is not a useful part of this. My kids are perfectly able to install linux on a pi - and this is something I want to encourage in general (I don't think they have, but they could), thus giving them root access - including access to things in the package repo that I may not approve of. It is a hard problem and I can't always be there.
I can flash my id to a bartender who doesn’t need to take a copy or otherwise retain my PII to serve me. This isn’t how we do age attestation in most cases right now. We require a third party to issue and verify identity and said third parties have been show to be poor stewards of our identity.