Research And Design Of Secure E-cash Payment System

E-commerce has been greatly developed as Internet becomes widely used. In e-commerce activities, a convenient effective payment method is very important.. There have been many electronic payment methods on the world, such as credit card, e-check, online banking etc. But none of those can meet the requirement of dramatic increment of online shopping. Online shopping needs a more convenient, effective payment method. E-cash is designed for this purpose.The research and design of e-cash payment system must be based on modern cryptology technologies. It wants to generate series of binary information in the electronic world to implement the functionalities of "cash". That is to say, it can achieve unforgeability, anonymity, divisibility, exculpability, no double-spending under the control of software.The main body of the paper is to design an e-cash payment system, but also includes some analysis and summaries of base theories. These come to following aspects: firstly, do some research jobs about e-cash system features, catalogs, current development status and future development; Secondly, summary related modern cryptology technologies especially RSA algorithm, Schnorr blind digital signature, zero-knowledge proof etc, improve performance of RSA key generation by choosing random prime number in a particular way; Thirdly, analyze traditional e-cash key technologies, design a revocable anonymity off-line e-cash scheme based on Brands' e-cash scheme. This scheme requests numbers of equal single e-coins in a batch, and spend a collection of them in one time, so it achieves divisibility through an indirect way. Also, Anonymity, off-line and revocable anonymity method are proved in restrict mathematical way. Lastly, OOD is used for the system design, web services technology is used for encapsulation of the system, such that it is extendable and can be easily integrated. A prototype system was implemented for testing the scheme.