Security Electronic Commerce Protocol by the Third Kind Entities

In e-commerce protocols, malicious participants misbehave on their benefits. There is some work in analysis the application-protocols but little similar work about the foundation-protocols. To fill the gap we use semi-regular entities to denote the entities different from penetrators that participate in the protocol on behalf of themselves such as customers in e-commerce. A method in strand space model is also presented. After descriptions of hash and Diffie-Hellman exchange, semi-regular strand and semi-regular node are added into the model, finally is an attack on the Internet key exchange (IKE) protocol as a case