Cryptanalysis of a key agreement protocol based on chaotic Hash
With the rapid development of theory and application of chaos, the chaotic Hash has been widely used in cryptosystems. Recently, Guo and Zhang proposed a secure key agreement protocol based on chaotic Hash. They claimed that their protocol could withstand various attacks. Unfortunately, by giving concrete attacks, we demonstrate that Guo and Zhang's protocol is vulnerable to the offline password guessing attack. The analysis shows their protocol is not secure for practical application.