The Study On Security Analysis Of Chaos-based One-way Hash Function

With the rapid development of network communication, computer technology andinformation industry, the research on the information security technology based on chaostheory is becoming increasingly important. Chaos, for its sensitivity to initial state andparameters, ergodicity, and unpredictable property, is well applied to construction of one-wayhash function. However, as MD5, SHA algorithms have been cracked which had beenregarded as the most secure algorithm, and some classical one-way hash algorithm based onchaos theory also exposes serious flaws. Therefore, the researchers should conduct in-depthsecurity analysis and research to construct secure chaos-based one-way hash algorithms.Chaos-based one-way hash algorithm is not absolutely safe and reliable, consequently, itshould undergo rigorous performance and security analysis before it can be put into trial. Thispaper focuses on the security analysis of the chaos-based one-way hash function and it hasimportant theoretical and practical significance to construct safe and practical algorithm. Themain works are as follows:Firstly, a parameters-changeable parallel hash algorithm based on chaos map wasanalyzed and improved. It is found that the main limitations are the error using of floor, roundand exclusive OR operations in the algorithm. In order to counterstrike these, someimprovements are done to strength its security. Theoretical analysis and experimental resultsillustrate that the improved hash function is more secure and practical than the original one.Secondly, a parallel spatiotemporal-chaos-based one-way hash algorithm was analyzedand improved. The original algorithm is simple and efficient, and the sub-block can runindependently. By theoretical and experimental analysis, we found it is vulnerable to theforgery attack, some improved measures of Hash value shift and matrix multiplication areproposed. The new algorithm has good collision resistance and high security, which wasconfirmed by the theoretical experimental analysis.Thirdly, the classical chaos-based one-way hash algorithms proposed in recent years areanalyzed and summarized. Defects are pointed out in some of them, and some of them werefound defects, then the reasons of which were given, and some possible improved measureswere proposed. On this basis, the general steps to constructing chaos-based hash functionalgorithms and security analysis were concluded.