International Association for Cryptologic Research (IACR)
Abstract
Recently, many non-interactive deniable authentication (NIDA) protocols have been proposed. They are mainly composed of two types, signature-based and shared-secrecy based. After reviewing these schemes, we found that the signature-based approach can not deny the source of the message and thus can not achieve full deniability; and that, the shared-secrecy based approach suffers KCI attack although it can achieve full deniability. In addition, both types of schemes lack efficiency consideration for they mainly base on DLP, factoring, or bilinear pairing. Due to this observation, in this paper, we use the Fiat-Shamir heuristic method to propose a new ECC-based NIDA protocol which not only can achieve full deniability but also is more efficient than all of the proposed schemes due to the inheritent property of elliptic curve cryptosystem. Further, we prove the properties of full deniability and KCI resistance conflict for a NIDA protocol. Besides, we deduce that a NIDA protocol is deniable if and only if it is perfect zero-knowledge
