I'm looking for a book that contains the formal definition of sigma protocol (something like: A sigma protocol for a relation $R$ and a challenge space $C$ is... that satisfies the properties of soundness..., completeness..., honest verifier zero-knowledge...)
I keep finding books that gives an example of sigma protocol, and they somehow discuss the main properties, but what I would like is a reference with an abstract definition.
I need it for a course for students of mathematics, who are used to read the formal definition of objects.
Thanks for any help
