The Study Of The Encryption In Electronic Commerce Security

With the high-speed development of the Internet, the human is entering a new era of the Internet information. It not only offers convenience to communication, but also changes classic business and economic paradigms. Electronic commerce based on Internet has become a new mode for people to pursue commerce. The prospect of Electronic Commerce is becoming more and more attracting. However, the security in Electronic Commerce is doubted because of the continuously occurrence of insecure events, so its security problem has become extraordinarily salient.This thesis is about encryption for electronic commerce based on the chaos theory.Firstly, according to the structure of security frame system for electronic commerce, the firewall, encryption techniques, authentication techniques are reviewed. Secondly, this thesis systematically described the definition and characteristics of chaos from the perspective of Chaotic Dynamics, discussed the ways to measure chaotic systems, introduced some typical chaotic systems and studied the relationship between chaos theory and cryptology.Then, the improvement algorithm was proposed: Combined the m-seqence perturbation compound chaos sequence encryption algorithm. In the improved algorithm, the Logistic system is replaced by Cubic system, and two different one dimension chaotic systems are applied, therefore, the Key-space is enlarged and the security of algorithm is ensured. And next a comprehensive analysis was made in the aspects of the improved algorithm which produced from sequence randomness, the complexity of linear sequence as well as the sequence security, and last a contrastive analysis was made among the traditional algorithm, the sequence carried before the improvement.The more secure Hash function was put forword an exchange of high-order and low-order in a proposal using higher dimensional Arnold cat chaos system to construct Hash function, and a chaos Signature Scheme. From the analysis of modular arithmetic used in the higher dimensional Arnold cat mapping, and the application of modular arithmetic is to change a big number into a definite numerical range, so modular arithmetic is sensitive to the change of low-order digit. But for high-order digit, especially for the digit beyond the modular range, once it is changed, the same value may be got after the modular arithmetic, thus the collision occurs.