Proposal: Commit-and-Prove Zero-Knowledge Proof Systems and Extensions

Commit-and-Prove Zero-Knowledge Proof systems (CP-ZKPs) [Kil89, CLOS02] generalize zero-knowledge proofs where we prove statements about values that are committed. In this document we propose this notion and its variants. It can be useful as a lingua franca framework because: it emerges in a wide variety of practical applications; it may unify abstractions and simplify proofs in cryptographic technical reports; although the notion is defined as a special case of NIZKs, some of its efficient constructions are non-trivial. While previous editions of the ZKProof workshop have confirmed interest in the formalization in this document, there is still significant work ahead in terms of: refining the content of the proposal, and describing existing candidate constructions as well as general design approaches.