Research For Multi-Bank E-Cash Protocol Embeded Expiry Without TTP

E-commerce system is now developing at an enormous speed, whose finalobjective is to electrize every phase of commercial activity. But the realelectronic transactions in which the payments are initiated on-line are very few.Electronic payment is the core of electronic commerce. How to achieve safe andfair electronic transaction as well as not reveal the intimacy of customers is thekey to the development of electronic commerce. The technology of e-cash is themain technology to resolve those problems. The goal of this dissertation is toresearch how to express e-cash base on Elliptic Curve Cryptosystems and howto realize multi bank protocol satisfied with atomicity and anonymity.We focus our research on following aspects: (1)The relevant knowledge about crypto graphical techniques is summariz-ed. The main techniques with electronic commerce are analyzed. The mode andfunction of PKI which is the basis establishment of public key are introduced.(2)The development history and the research present situation of E-cashsystem's anonymity problem are summarized, and the efficiency of bank's data-base in E-cash system is analyzed. We point out that validity duration of E-cashcan improve the fficiency of bank's database;without trusted third party canreduce the system's burden and realize anonymity-revocable.(3)An off-line E-cash system with validity duration Without TTP is present-ed base on limited blind signature and a multi bank protocol that can enableatomicity and fair anonymity commendably is presented and the process ofwhich is elaborated.(4)The presented protocol of electronic commerce is analyzed. The atomi-city, anonymity-revocable, and safety of protocol are validated with the analysisof protocol's efficiency.The elliptic curve cryptosystems are analyzed in the paper. How to realizedigital signature is presented. The e-cash is presented use those signaturerespectively. The e-cash base on limited blind signature can guarantee to realizethe multi bank protocol effectively.