Zhuang Huanguo and his group of researchers at the Key Laboratory of Aerospace Information Security and Trusted Computing developed the new cryptosystem over a decade, according to a release by Science in China Press.
Up to now, cryptosystems have been designed to encrypt and decrypt data using fixed algorithms and randomly changed keys, the release stated. Evolutionary cryptography, which draws on analogies from biology, is based on alterable algorithms that are replaced periodically with cryptographically stronger ones, it added.
“In general, the resistance against some known cryptanalysis of a cryptosystem mainly depends on some of its fundamental cryptographic components. For instance, the nonlinear cryptographic component S-boxes and the linear permutation used to produce confusion and diffusion in block ciphers play a crucial role in resisting differential cryptanalysis and linear cryptanalysis. A variety of attacks [have] been found against the known cryptosystems, and these consequently lead to criteria cryptographic components must satisfy”, the release explained.
Linear and differential cryptanalyses are two widely used attack methods on iterated block ciphers, and both are used as tools in evaluating the security of block ciphers. In the past two decades, improvement in employing linear attacks has been made, the most significant being a multidimensional extension of original linear cryptanalysis, the release said.
In his research, Huanguo exploited separately the security of evolutionary block cipher against multidimensional linear cryptanalysis and differential cryptanalysis. Based on a comparison of the complexity and success rate between the two types of cryptanalysis, the research results indicate that the evolutionary block cipher performs more securely and robustly than the initial fixed-block cipher with regard to resisting these two important attacks, the release concluded.