The Solution To Electronic Cash System Within Multiple Banks Based On ECC

E-commerce system is now developing at an enormous speed,whose final objective is to electrize every phase of commercial activity.Electronic payment system is kernel of E-commerce system.Although the electronic payment system based on E-cash is still under developing ,it might be widely used beause of it's advantage.This thesis presents a solution of E-cash system with multiple banks on ECC .It focuses on sloving security problem on circulation,deposition and withdrawl of E-cash process,and strives to improve the system's efficiency.The E-cash's divisibility is a problem of E-cash system research.This thesis transforms divisibility problem to exact payment problem which means that a user withdraws many coins of different denominations during withdrawal period,then uses a subset of these coins to provide the extra payment during payment period.How to get the optimal set of coins and how to accomplish payment with the set are the keys to solve the divisibility problem.The solution of above two problems is using greedy payment algorithm and N- divisibility algorithm.This dissertation proposes a multi-bank,anonymity-revocable E-cash system by using restrictive blind group signature technology.The author apply Elliptic Curves Cryptosystem in the scheme.In this system the central bank is the group-manager and banks,issuing E-cash ,are group members.E-cash can be validated by a unique group public key .Trusted third party is introduced into this system to make it capable of tracing E-cash and withdrawer.In the thesis,the author design an efficient fair off-line electronic cash system base on Elliptic Curve Discrete Logarithm Problem(ECDLP), make the research of e-cash system has an important advance in practicality.