Trait allowing cryptographic proof of membership of a set with known members under multiple
contexts without exposing the underlying member who is proving it and giving an unlinkable
deterministic pseudonymic “alias” under each context.
Cryptographic identifier for a person within a specific application which deals with people.
The underlying crypto should guarantee that all Alias values used by a person to represent
themself for each Context are unlinkable from both their underlying PersonalId as well as
all other Alias values of theirs.