The Research On Electronic Cash System Based On FI05 Group Signature

With the rapid development of electronic computer and Internet , electronic commerce has attract more attention as a new commerce mode, more and more merchandise will circulate through the online transaction. The center issue of electronic commerce is the secure electronic payment. As a new method of payment, electronic cash has the advantage of protecting user's anonymity and untraceability compare with the credit card and electronic check, so it will be more suitable for need of the electronic payment.As a special digital signature, group signature offers the ability to hide interior structure of the organizing. It has characteristics such as anonymity, unforgeability and so on. So it can be widely used in electronic commerce and lots of other domains. At present, many electronic cash system is constructed by group signature. however, a lot of questions have not been solved such as unefficient, membership revocation, transferability, divisibility, and so on.This paper deals with the study of an electronic cash system of multiple banks based on the group signature. Aiming at the existent problems of the group signature and electronic cash, we design a new group signature with member revocation and then establish a new electronic cash system of multiple banks with more functions.Aiming the membership revocation problem of group signatures at present, this paper first put forward a new dynamic accumulator and gives a new method to solve the problem of membership revocation base on the efficient FI05 group signature using the Accumulator.According to the security analysis, we proofs that not only the accumulator is secure but the new scheme meets all the security requirements of group signature.Secondly, we present a fair off-line electronic cash system with multiple banks based on the improved group signature scheme introduced above. This system provides the functions of preventing blackmailing the customers or banks and money laundering, identifying double-spending, member revocation and revocable anonymity for customers.Finally,A practical cash system with multiple banks is basically implemented based on Java and Oracle database.