Research And Realization Of Divisible E-cash System

With the rapid popularization of the computer network technology, electroniccommerce begins to develop quickly. Fair off-line e-cash system with security, efficiencyand divisibility has an important scientific and academic value. Moreover it has animportant significance to our electronic commerce, the information construction offinancial organizations and the development of our national economy. However,electronic cash is still on the stage of research and development so far. Many technicalproblems such as how to enhance efficiency and security and how to realize fairness anddivisibility haven't been solved completely.This paper devotes to the research of divisible e-cash systems, proposes two newdivisible e-cash schemes, and designs and realizes a divisible e-cash system without TTP(trusted third party), which carries on a beneficial exploration for a large-scale applicationof e-cash payment.Firstly, this paper introduces the basic knowledge of e-cash, including researchactuality abroad and at home, main system models and key technologies, and thenanalyzes the divisibility of e-cash systems.Secondly, two new divisible e-cash schemes are proposed. On the one hand, aimingat the problem that TTP has power centralization in a divisible e-cash system, distributedTTP can disperse the tracing power to n credible organizations, at least k of which canunite to realize tracing. The decentralization of TTP has avoided power centralization andcontrolled arbitrary tracing in a certain degree. On the other hand, aiming at the problemthat TTP causes uncertain tracing, an anonymity-revocable and divisible e-cash scheme isproposed without TTP. In this scheme, according to the clue and certificate provided bythe judicial organization, the bank requires the user to open the message with the sametime stamp, which can realize the trace to e-cash and withdrawer.Finally, a divisible e-cash payment system without TTP is designed and realized.According to client/server design structure and Visual C++ 6.0 development kits,adopting ODBC to visit SQL Server database, this system can realize the necessaryfunctions.