ZKBoo: Faster Zero-Knowledge for Boolean Circuits

In this paper we describe ZKBoo1 , a proposal for practically efficient zero-knowledge arguments especially tailored for Boolean circuits and report on a proof-of-concept implementation. As an highlight, we can generate (resp. verify) a non-interactive proof for the SHA-1 circuit in approximately 13ms (resp. 5ms), with a proof size of 444KB. Our techniques are based on the “MPC-in-the-head” approach to zero-knowledge of Ishai et al. (IKOS), which has been successfully used to achieve significant asymptotic improvements. Our contributions include: ◦ A thorough analysis of the different variants of IKOS, which highlights their pro and cons for practically relevant soundness parameters; ◦ A generalization and simplification of their approach, which leads to faster Σ-protocols (that can be made non-interactive using the Fiat-Shamir heuristic) for statements of the form “I know x such that y = φ(x)” (where φ is a circuit and y a public value); ◦ A case study, where we pr...

• Type: Journal
• Year: 2016
• Where: IACR
• Authors: Irene Giacomelli, Jesper Madsen, Claudio Orlandi
• Keywords: Biometrics, IACR 2016