Decentralized social network Mastodon says it cannot comply with age verification laws, like in Mississippi and elsewhere, and says it's up to individual server owners to decide.
Making the certs short-lived (a few minutes) and single use and having a rate limit for users could make it difficult enough with serious risks (if you make it a crime) for little profit (I doubt many kids will pay serious amounts of money to watch porn; definetly not drug-scale amounts of money).
I was using the wording of OP who seems to be talking about tokens. The service asks the trusted entity if the token is valid, the trusted entity deletes the token after the first time.
Making the certs short-lived (a few minutes) and single use and having a rate limit for users could make it difficult enough with serious risks (if you make it a crime) for little profit (I doubt many kids will pay serious amounts of money to watch porn; definetly not drug-scale amounts of money).
You cannot make a certificate “single use” (except if it exists only inside a closed system).
I was using the wording of OP who seems to be talking about tokens. The service asks the trusted entity if the token is valid, the trusted entity deletes the token after the first time.