This paper aims to improve SHA-512 security without increasing complexity; therefore,
we focused on hash functions depending on DNA sequences and chaotic maps. After analysis of
45 various chaotic map types, only 5 types are selected in this proposal—namely, improved logistic,
cosine logistic map, logistic sine system, tent sine system, and hybrid. Using DNA features and
binary coding technology with complementary rules to hide information is a key challenge. This
article proposes improving SHA-512 in two aspects: the modification of original hash buffer values,
and the modification of additive constants Kt. This proposal is to make hash buffer values (a, b, c,
d, e, f, g, and h) and Kt dependent on one-dimensional discrete chaotic maps and DNA sequences
instead of constant. This modification complicates the relationship between the original message
and hash value, making it unexpected. The performance of the proposed hash function is tested
and analyzed the confusion, diffusion, and distributive and compared with the original SHA-512.
The performance of security is analyzed by collision analysis, for which the maximum number of
hits is only three, showing that the proposed hash function enhances the security and robustness of
SHA-512. The statistical data and experimental analysis indicate that the proposed scheme has good
properties and satisfies high-performance requirements for secure hash functions. |
