Zero-Knowledge Proofs with Witness Elimination

Abstract. Zero-knowledge proofs with witness elimination are protocols that enable a prover to demonstrate knowledge of a witness to the verifier that accepts the interaction provided that the witness is valid for a given statement and additionally the witness does not belong to a set of eliminated witnesses. This set is determined by a public relation Q (that parameterizes the primitive) and the private input of the verifier. Zero-knowledge proofs with witness elimination thus call for a relaxation of the zero-knowledge property and are relevant in settings where a statement has a multitude of witnesses that may attest to its validity. A number of interesting issues arise in the design of such protocols that include whether a protocol transcript enables the verifier to test for witness after termination (something akin to an “offline dictionary attack”) and whether the prover should be capable of understanding whether her witness is eliminated. The primitive is motivated by the...

• Type: Conference
• Year: 2009
• Where: PKC
• Authors: Aggelos Kiayias, Hong-Sheng Zhou
• Keywords: PKC 2009, Witness Elimination, Zero-knowledge Proofs, Zero-knowledge Property