On Probabilistic versus Deterministic Provers in the Definition of Proofs Of Knowledge

Webpage for a paper by Bellare and Goldreich


This note points out a gap between two natural formulations of the concept of a proof of knowledge, and shows that in all natural cases (e.g., NP-statements) this gap can be closed. The aforementioned formulations differ by whether they refer to (all possible) probabilistic or deterministic prover strategies. Unlike in the rest of cryptography, in the current context, the obvious transformation of probabilistic strategies to deterministic strategies does not seem to suffice per se.

This note refers to and is heavily based on the definition (of proofs of knowledge) that was put forward in our paper On defining proofs of knowledge (1992).

Material available on-line

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