Design Of Parallel Cryptographic Hash Function Based On Chaos

Hash functions are the fundamental components in modern cryptography and also key modules in information security system and private communications protocol. Hash functions are widely used to achieve certain security goals such as data integrity, message authentication, digital signature, etc. As an important means to ensure the safety of information, Hash function must make sure that it itself is safe. After the traditional Hash function was successively proved to be unsafe, the researches of hash function based on chaos system have become a hot spot in the field of information security.The following tasks have been accomplished in this thesis:(1) The basic knowledge of cryptography hash function and chaos theroy are introduced. First, the definition of Hash function, properties, application, classification, and common iterative structure and evaluation method are introduced. Meanwhile, in order to give a description of the practical application value of hash function based on chaos theory, this paper lists several basic models for chaos theory, analyzes the advantages and disadvantages of chaotic mapping which is used to form the one way hash function, and combines several hash functions based on chaos theory.(2) According to the analysis of the classical Hash function and exiting chaotic Hash function, this thesis puts forward a chaotic hash function, which is based on spatial expansion construction with controllable parameters. The algorithm draws on the idea of Rubic’s cube, combined with spatial expansion characteristics of the structure. The dynamic key control message of the mode of operation in space, which includes inflation, contraction and substitution, improves the system’s confusion and diffusion properties. The parallel operation model improves not only the security of the Hash function but also the system performance. Theoretical and experimental results show that the proposed method has high performance in parallel algorithm, nearly uniform distribution and desired diffusion and confusion properties.(3) A parallel hash function using DM-based integer-valued chaotic maps network is proposed which combines the advantage of both chaotic system and DM scheme. And the algorithm has avoided the flaw of the forgery attack of the exiting parallel hash functions, and complex chaotic operation can be replace by simply shift, or operation, which reduces the chaotic operation time.At the same time, the Sponge structure can provide different length of Hash value according to the input paramteter changes.In the operating mode of the configuration, the algorithm also has flexibility, there are two operation modes can be selected in the proposed hash function which are parallel operation mode and serial operation mode. Theoretical and simulation results show that the proposed hash algorithm has strong diffusion and confusion capability. Through the FPGA software simulation, parallel operation mode of the Hash function has higher efficiency.Finally, the research work of this dissertation is summarized, and the futuredeveloping direction is indicated.