A secure non-interactive deniable authentication protocol based on discrete logarithms

A deniable authentication protocol has two important security properties: authentication and deniability. Authentication allows the intended receiver to identify the source of a given message, and deniability prevents the intended receiver from proving the identity of the sender to a third party. Based on ElGamal signature cryptography, Wang et al. recently proposed a simple deniable authentication protocol to achieve these two requirements. However, in this paper, we pointed out that Wang et al.'s protocol violates their claimed security requirements and further proposed a new efficient non-interactive deniable authentication protocol based on discrete logarithms to overcome the security aws inherent in Wang et al.'s protocol. As compared with Wang et al.'s protocol, the performance of the proposed protocol is more efficient than that of Wang et al.'s protocol in terms of the computational complexities and the communication costs.