Maybe I missed something, but with your proposed solution, what would stop someone from just handing the adult cryptographic token to a kid? It sounds like it would be a similar situation to or even easier to do than fake ID cards or adults buying alcohol for underage people.
Nothing. Who says a solution has to be perfect? If “good enough” is good enough for handling the sale of alcohol, it can certainly be good enough for accessing web sites. No solution to any problem is perfect. You always have to find a balance between preventing the thing you want to stop and the negative effects of your efforts to prevent that thing.
Maybe I missed something, but with your proposed solution, what would stop someone from just handing the adult cryptographic token to a kid? It sounds like it would be a similar situation to or even easier to do than fake ID cards or adults buying alcohol for underage people.
Nothing. Who says a solution has to be perfect? If “good enough” is good enough for handling the sale of alcohol, it can certainly be good enough for accessing web sites. No solution to any problem is perfect. You always have to find a balance between preventing the thing you want to stop and the negative effects of your efforts to prevent that thing.
In that case, I suppose I agree with your solution.