Identity Based Cryptosystem Using In Fair Electronic Contract

Electronic contract is the hotspot in current electronic commerce application, To solve the problems of fair electronic contract, the Identity Based Cryptosystem is proposed, using in exchangeing the signature of Two-Part Fair Electronic Contract protocol and Three-Part Fair Electronic Contract protocol. We discussed some details on security in reality, main works is: (1)A survey on current Fair Electronic Contract, and some problems is given.(2) Using the idea of Identity Based Cryptosystem ,we can create the user's public key from his Identity.It is very helpful for the creation and management of user's secret key in electronic contract.(3) On protecting of message in electronic contract, the public key signcryption scheme is proposed,it can perform encryption and signature in a single logical step in order to obtain non-repudiation and confidentiality, that is helpful for protecting the content of electronic contract.(4) Applying a efficient Fair Electronic sign exchanging protocol.It is useful for people to exchange their signature.The interceder will take part in the protocol only when there is something wrong with the communication or somebody cheating in the protocol,and he dose not increase the load of communication.(5) The Two-Part Fair Electronic Contract protocol and the Three-Part Fair Electronic Contract protocol is discussed separately,we can extend the users to Multi-Part when it is needed.It is provable our protocol has good expansibility.