Performance Analysis And Design Criteria Of Chaos-based Hash Function

With the rapid development of Internet and e-commerce, the security of messagetransmission and storage is becoming more and more important. Therefore, the Hash function,one of the key technologies of the modern information security, has been widely concerned byresearchers. After MD5 algorithm has been cracked, the classic one-way Hash function hasalready exposed some flaws, so how to construct a secure Hash algorithm, and it needs tomake a deep study. The Hash function construction based on chaos theory has also become ahot research field of information security simultaneously.The dynamic behavior of chaotic systems is very complicated, and it has randomness,ergodicity, and sensitivity to the initial condition and chaotic parameter of system, which arequite suitable to construct Hash function. Hash algorithms based on chaos theory haveachieved fruitful achievements, however, these algorithms are not absolutely safe. To ensurethey are safe to use, these algorithms should be sufficiently analyzed and proved, before itputs into practice. The main work of this paper include security performance analysis ofchaotic Hash function and its flaws, corresponding improvements, and study of designprinciples, which has important theoretical and practical significance. The main work of thispaper is listed as follows:1. The Hash Algorithm based on chaos coupling mapping was analyzed, and the existingweak sensitivity and forgery attack were found in the original algorithm. We try to change theselection method of middle sequence value and the final Hash value to resolve the two defects.Analysis is done to the improved algorithm, and it shows that the improved algorithm hasgood confusion and diffusion properties, well collision resistance and sensitivity toplaintext.Thereafter, it points out that more attention should be paid to establish theconnection among the plaintext in design of parallel hash funtion.2. Several typical chaos-based hash function algorithm proposed in recent years are analyzed,and some defects are found, then summary is made for the construction of the hash function inseven aspects, which are easy to cause defects. Finally, the general method to construct thechaos-based hash function is proposed, and seven principles are point out to be paid attentionby designer.