That's nowhere near being "just" a cipher :) "A cipher that lets the format be validated" is precisely what a ZKP is, though nobody calls it a cipher. (Crypto

That's nowhere near being "just" a cipher :) "A cipher that lets the format be validated" is precisely what a ZKP is, though nobody calls it a cipher. (Cryptographic signature is a simpler form of ZKP though, where the proof doesn't require any back-and-forth)