Commit-and-Prove protocols allow one party to commit to a value and prove that the value satisfies a given predicate, while ensuring that this value remains hidden. Such protocols are often used in the construction of MPC protocols. Black-box commit-and-prove protocols are those that use the composite primitives without looking at the underlying code, and are often preferred due to efficiency reasons. One salient measure of the complexity of such protocols is the number of rounds of communication.
In this talk, we will see a three-round commit-and-prove protocol by Hazay and Venkitasubramaniam that satisfies constant soundness and zero-knowledge. We will also see the construction by Khurana, Ostrovsky and Srinivasan that boosts the soundness when the zero knowledge requirement is relaxed to witness-indistinguishability.
References:
1. On the Power of Secure Two-Party Computation
2. Round Optimal Black-Box "Commit-and-Prove"
