Study And Application Of Several Protocols And Specifications For Fair Exchange

Fair exchange protocols and specifications play an important theoretical role in its realization and thus considered indispensable in security study.In this dissertation, some protocols and specifications for fair exchange have been studied and some new ideas are also proposed. The primary research is summarized as follows.1. Fair guideline. Fairness essentials are analyzed thoroughly. A fair guideline has been presented, which is fit for fair exchange protocols. Moreover, fairness level is discussed and a group of definitions is presented, which classifies protocols into three levels. Meanwhile, some conclusions on difference of fairness are also given.2. Fair information exchange. Two kinds of fair exchange protocols, gradual exchange and third party protocol, are discussed. The idea of conditional TTP has been developed on the basis of semi-trusted TTP. A common fair exchange and a non-repudiation protocol based on off-line conditional TTP are given.3. Fair logic. Logic sentences and principles for fairness analysts are defined to authenticate whether a participant can get condign messages that come from right entities or not, in order to reach fair acquirement analysis. Further, the new logic is adopted to analyze two representative fair exchange protocols in order to show the applied way and the result of the new one.4. EMV smartcard payment specification. Protocol flow and security mechanism of EMV, a most widely used smartcard payment specification, are studied systematically and some important assumptions are obtained. Further analysis shows that there exists some weakness. Improving advice is proposed without modifying the flow of application.5. Chip electronic commerce (CEC). System structure of CEC is discussed and the cardholder system, the interface of EMV and SET, is studied. Two feasible implemented schemes are put forward and properties of them are compared.