文中对 SET协议中的“k out of n”问题进行了全面的分析 ,并提出了完整的解决方案 .在对 SET付费业务流程中的两个关键性问题用 NDL逻辑进行验证后 ,给出了它们的 Prolog程序流程 .全文着重于在 SET协议中实现“防抵赖”和“可追踪”两种安全机制 ,并在此基础上实现用 Prolog语言程序模拟验证过程 .最后对电子商务的发展和今后将要做的工作做了一些初步的探讨 In this paper, the “k out of n” problem in SET protocol is analyzed in detail and a complete solution is proposed.After verifying the two key problems in the SET payment business process with NDL logic, Their Prolog program flow.The full text focuses on the realization of two kinds of security mechanisms of “non-repudiation” and “traceability” in the SET protocol, and on this basis, it realizes the verification process with Prolog language program.Finally, the development of e- Do some preliminary work to be done