Research On Chaotic Hash Function Based On OHNN

In recent years, with the rapid development of computer and networkcommunication technology, people communicate on the network more frequently.How to protect the security of information during the communication is becomingmore and more important. In the field of cryptography, hash function has been widelyused in digital signatures, message authentication and data integrity protection. But,with the breakthrough of study of hash collision, the traditional hash algorithmswhich are widely used such as MD-5, SHA-0, SHA-1, etc., have been proven unsafeenough. Therefore, it is very important to study and design a new hash algorithmwhich is much more safety.Chaotic system has many good features such as its sensitive dependence oninitial conditions, extreme sensitivity parameters, the system tracks traverse andunpredictability, etc., and become a research focus in cryptography. After years ofdevelopment, chaotic system has been widely applied in the areas of stream ciphersand block ciphers. The dissertation will use the theory of chaotic neural networkdesigning a new Hash algorithm.Firstly, the dissertation studies carefully on the theory of cryptography andchaotic system, and analyzes the different systems of cryptography and severaltypical chaotic systems. We focused on the study of the principles of OverstoragedHopfield neural network attractor and its nonlinear characteristics. And thecalculation method of attractors was detailedly analyzed.Secondly, the dissertation studies and introduces some principles of designing achaotic Hash function. After analyzing the chaotic characteristics of piecewise linearfunction and OHNN attractor, a new Hash function algorithm based on OHNN wasproposed. And the principle and process of the algorithm was detailed introduce too.Finally, the performance of the proposed algorithm in this paper was tested andanalyzed systematically. During the analysis, a statistics method which is NISSIEproject testing the complete, the avalanche effect and strict avalanche accurate wasintroduced to do a qualitative analysis on the nonlinear diffusion extent of the new chaotic Hash algorithm. After theoretical analysis and practical test, as well ascomparison with other Hash algorithm, the results show that the proposed algorithmcan resist Chaos Hash collision attacks, attacks, attacks and birthday statisticalanalysis, and verify its good safety performance.