> Bob trusts all 50 issuers, but Alice doesn't want to reveal who her issuer is.
So, just a form of certificate chaining? With the same old challenges that come up if Bob learns that one of the issuers was compromised for some period of time?
Sorry, what is certificate chaining in this context?
ZKP allows you to run arbitrary logic, without the id providers having to anticipate what you are trying to do nor having to cooperate. Eg you could prove that 'either your age is a prime number or that you have green eyes and live in New York'.
Let me be more blunt: I don't think certificate chaining is a useful concept in this context, but I wanted to be more polite about my objection and give you a chance to explain your idea. Better?