With the rapid development of Internet, network is widely used in all fields of people's life. It provides more opportunities to people, and some companies have paid more attention to electronic commerce than traditional commerce. However electronic commerce cannot avoid security problems. What is more, a secure payment system is of great importance to guarantee the security of electronic commerce.As for electronic pay protocol, many protocols have been researched, such as secure electronic protocol, which is used in the practice. First of all, we research Secure Electronic Transaction (SET), then we give an advanced electronic pay protocol named A-SET with the regard of public business information terminals. A-SET inherits the securities of SET. It rectifies the transaction flow of SET and guarantees atomicity and non-repudiation of transaction to the full extent. As a result, it assures the impartiality of both sides.After giving an advanced electronic pay protocol named A-SET, we apply it in Multi-Business Online Trade System (MBOTS) and it guarantees the security of this system. The system can be divided into five parts: Terminal Browser, Merchant Transaction System, Secure Payment System, Virtual Bank and Certificate Authority. In the system, Terminal Browser provides the interface to users. Virtual Bank provides virtual accountants to the participants. And Certificate Authority is responsible for the management of certificates of the participants. At the same time we design and implement Secure Payment System to provide a general interface of credit-card authorization. Merchant Transaction System mainly processes transaction requests from Terminal Browser. |