International Journal of Network Security
In 1998, the researchers first proposed an application of zero-knowledge, deniable authentication protocol. Thereafter, there were many researches about the deniable authentication schemes. In 2004, they demonstrated out that the previous schemes had a common weakness in which any third party can impersonate the intended receiver to verify the signature of the given message and they proposed a new scheme based on ElGamal signature scheme. Although, they claimed that the users scheme could provide complete security and properties of a deniable authentication scheme, the authors will point out that the researcher's scheme is unable to achieve the second requirement of the deniable authentication scheme.