A deniable authentication protocol enables a receiver to identify the source of a given message, but the receiver cannot prove the source of the message to a third party. Recently, Yoon et al. (Wirel Pers Commun 55:81-90, 2010) proposed a robust deniable authentication protocol based on ElGamal cryptosystem. Although they proved that their protocol satisfies the deniable authentication, mutual authentication and confidentiality, we show that their protocol does not satisfy the deniable authentication property. The receiver can prove the source of a given message to a third party. In addition, we propose an improved protocol that removes this weakness.
All Science Journal Classification (ASJC) codes
- コンピュータ サイエンスの応用