The Research Of Hash Function Based On Spatiotemporal Chaos

With the rapid development of cryptanalysis, especially after MD5 and SHA-1 were deciphered by Chinese scholars, the security of traditional Hash function faced a serious security problem which draws a widespread attention all over the world. The development of the chaos theory brings new ideas to the research of Hash function. Because of the advanced characteristics of the chaos system, construction of a Hash function based on the chaos system is becoming a hot subject in the academic circle.In order to solve the problems in present construction methods of Hash functions based on chaos system, and improve the performance of Hash functions, this thesis makes an in-depth study and research of Hash functions based on Spatiotemporal Chaos. After analyzing the construction methods of Hash functions based on chaos and studying the system of Spatiotemporal Chaos, this thesis focuses on a typical model of Spatiotemporal Chaos system - crossing coupled map lattice and dicovers the unique property of Spatiotemporal Chaos and thus proves the feasibility and advantage of crossing coupled map lattice to build the Spatiotemporal Chaos system. On the basis of all these above, this thesis presents two algorithms of Hash function construction based on crossing coupled map lattice and implements the algorithms in DSP. Through the simulation experiments, the sensitivity of the initial value, the diffusion ability, the collision-free ability, the implementation of efficiency, and the expansibility are analized to prove that these two algorithms can satisfy all the performances requirements of Hash function. Hash functions constructed by these algorithms have high security and extensibility and have the potential to become a secure and practical Hash function.