期刊名称：International Journal of Computer Science and Information Technologies
电子版ISSN：0975-9646
出版年度：2012
卷号：3
期号：3
页码：4421-4426
出版社：TechScience Publications
摘要：The main contribution of the paper containing two steps, one is building stepby step a chaotic hash function starting from a weak but basic algorithmand second is analyzing its strengths and weaknesses in order to make it stronger.We start with a basic chaotic hash function with a 256-bit message digestbased on Baptista’s encryption algorithm. In the next steps, a pseudorandomnumber generator using chaotic tent map is incorporated within the hash algorithm and perturbation and block chaining approaches areused to strengthen the hash function. We have carried out both the preimage and secondpreimage resistance analysis and proved that the proposed hash function is strong against both these attacks. Further, the standard collisionanalysis is performed in the space of 1-bit neighborhood of a given message.The hash function is shown to exhibit diffusion effect with averagehamming distance between message digests obtained as 127 bits which isclose to the ideal of 50%. The collision performance compares favorably with that of chaotic hash functions proposed in the recent literature. Itis to be emphasized that the existing chaotic hash functions in the literatureuse a multitude of chaotic maps whereas we show in this paperthat using two chaotic maps judiciously achieves a secure hash function.
关键词：Chaotic Hash function; Pseudo Random Number;Perturbation; Hamming distance; Message digestcs..
