An Improved Two-party Password-Authenticated Key Agreement Protocol with Privacy Protection Based on Chaotic Maps

Since the 1990s, chaotic systems have widely used to cryptography which can be used to design kinds of secure protocols, digital signatures, hash functions and so on. Recently, Guo and Zhang proposed an chaotic public-key cryptosystem based key agreement protocol. In 2015, Lee has proved that Guo et al.’s scheme cannot resist off-line password guess attack. Then, Liu and Xue further point out that Guo et al.’s scheme has redundancy in protocol design and still has some security flaws. In this paper, we further prove that Liu’s scheme has four flaws at least and a potential loophole. Moreover, these papers provided no privacy protection which is a very important property in the modern social network. So an improved Two-party Password-Authenticated Key Agreement Protocol with Privacy Protection is proposed for amending these flaws and loophole. Compared with the related literatures recently, our proposed scheme can not only own high efficiency and unique functionality, but is also robust to various attacks and achieves perfect forward secrecy. Finally, we give the security proof and the efficiency analysis of our proposed scheme.