Hash Function Algorithm Based On Chaos System

In the 21 st century,the Internet is booming.Network communication has become the main channel to communicate with each other.People also face the risk of divulging information when they access information through the Internet.Therefore,to ensure information security,authentication of information has become one of the research hotspots in cryptography.In the process of authenticating messages,Hash function is a commonly used technology.Hash function with good performance needs strong sensitivity,confusion and diffusion characteristics for plaintext messages,while chaotic maps have initial sensitivity and iterative unidirectionality.These features are very suitable for designing hash functions.The paper designs Hash functions based on serial and parallel structures respectively,analyzing the security of the algorithm,and improving the computational efficiency of the algorithm.The main research content of the paper includes:1.The Hash function based on the parallel structure processes the plaintext message in blocks,so the intermediate hash value generated by each message block does not have a strong sensitivity to the position of the message block in the original plaintext.Therefore,the final Hash result generated by XOR operations is vulnerable to forgery attacks.For this problem,a new parallel Hash function based on chaotic map is proposed.In the pre-processing phase of plaintext,the algorithm changes the value of the plaintext by iterating a piecewise Logistic map and enhances the connection between the plaintext bytes.Theoretical analysis and experimental results show that the algorithm possesses good plaintext sensitivity,confusion and diffusion characteristics and collision resistance.Therefore,the proposed algorithm can resist forgery attacks.2.The paper reference a confusion method from the image encryption algorithm,analyzing its confusion performance and its feasibility in the hash function.It was found that although this method has good confusion performance,it has poor confusion effect on the special arrangement of plaintext values.For this problem,the paper improves it,and then proposes an improved confusion method based on the piecewise logistic map.Theoretical analysis and simulation results show that the improved confusion method has better confusion performance and higher sensitivity to the original plaintext than the original method.3.The improved permutation method is used in the construction of serial Hash function.changing the position relationship of the plaintext value,confusing the value of the plaintext,so that the Hash value has a strong dependency relationship with the position of the plaintext value and the plaintext value.Theoretical analysis and experimental results show that the improved confusion method has good confusion performance for the original plaintext.Hash function has higher sensitivity,more stable confusion and diffusion characteristics and good collision resistance.Therefore,the proposed algorithm can meet the actual requirements for the application of information security.