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.
Yeah this. I don't know why people are trying to make this into some incredibly complicated multi step process.
I can't speak for every government in the world, but as far as the major ones go, USA, Russia, China - I have less than zero percent trust in any of their companies to handle my data in a private and safe way.
It just isn't happening. They will dissect it, sell the data points they can, surveil you with the other data points, train AI with it and all kinds of other shenanigans. And most people know this.
That's why you can't just go right in to doing that, gotta help me adults think they're helping children and society at large first. Start with something small, just a small inconsequential right they lose ("Oh, I have to input my age to access this site") and then raise the stakes a little ("Oh, now I have to input my picture ID, ok")
Until it escalates into full inescapable 24/7 surveillance against you. And far from before that moment in time its already too late.
Once they implement this, its already too late.
because it's the first step in a multi step attack on our privacy.