On the Concurrent Composition of Zero-Knowledge Proofs

We examine the concurrent composition of zero-knowledge proofs. By concurrent composition, we indicate a single prover that is involved in multiple, simultaneous zero-knowledge proofs with one or multiple verifiers. Under this type of composition it is believed that standard zero-knowledge protocols are no longer zero-knowledge. We show that, modulo certain complexity assumptions, any statement in NP has k -round proofs and arguments in which one can efficiently simulate any kO(1) concurrent executions of the protocol. Key Words: Asynchronous Attacks, Zero Knowledge, Black-box Simulation.

• Type: Conference
• Year: 1999
• Where: EUROCRYPT
• Authors: Ransom Richardson, Joe Kilian
• Keywords: Concurrent Composition, Cryptology, EUROCRYPT 1999, Simultaneous Zero-knowledge Proofs, Zero-knowledge Proofs