Research On Fair E-cash System

E-cash is a late-model electronic payment mechanism contrast to the paper currency. It is issued and value promised by the e-cash company (bank). As an excellent payment mode, the electronic cash have many virtues such as lower cost, higher security and off-line dealing and so on. Its emergence will contribute greatly to the development of Electronic Business.Presently, many systems with regard to the electronic cash payment have been developed. However, researches on electronic cash are in a phase of exploring in our country. so it is of great importance to develop an off-line electronic cash payment system with full functions, and how to realize fair exchange on the electronic cash payment system is the focus of research.The fair and efficient system presented in this article is a modification stealing from Brands scheme, which is considered as one of the most efficient e-cash scheme, and it keeps the characteristics of efficiency and security of the Brands scheme. By useing a certification scheme basing on E1Gamal digital signature and introducing the trustee, focuses to solve the comparatively difficult problem in e-cash system: fairness, and strives to improve the system's efficiency. In the scheme, the user must register to the trustee before trade. The client and the merchant must certificate each other by affirmance algorithm program when payment. In addition, the thesis proves the efficiency of the affirmance algorithm and the theme which to insure the fairness. The trustee is involved only during registration or when disputation occuring and is out-line during other stage, and such the efficience of e-cash is insured thereby. Basing on the studying of the exchange mechanism and system, the article bring forward the whole configuration and frame of the fair electronic payment system on layer-divided idea in the end.