In this paper, we proposed an improvement of SET protocol for E-commerce transaction. We study the security technology and protocol flow of set protocol, and point out the shortcomings of SET protocol. Due to the lack of security and low scalability of the current protocol, this paper proposes a server e-wallet strategy, which divides the original client into e-wallet client and e-wallet server, and enhances the convenience and security of the transaction by transferring the client to the issuer or the third-party financial institution, while the scalability is stronger. In order to ensure the atomicity of goods and confirm the atomicity of delivery, this paper proposes a secure e-commerce payment protocol based on the fourth party, which includes master protocol, customer return protocol, customer exchange protocol and customer merchant transaction dispute resolution protocol. According to the efficiency of SET protocol, a security hierarchical control model is proposed, which can select different security levels to operate according to the actual needs of customers, and the principle and implementation of the model are analyzed.

在本文中，我们提出了一种用于电子商务交易的SET协议的改进。我们研究了set协议的安全技术和协议流程，指出了SET协议的不足。由于当前协议缺乏安全性和可扩展性，本文提出了一种服务器电子钱包策略，将原始客户端分为电子钱包客户端和电子钱包服务器，通过以下方式增强了交易的便利性和安全性。将客户转移到发行人或第三方金融机构，同时可扩展性更强。为了保证商品的原子性和确认交付的原子性，本文提出了一种基于第四方的安全电子商务支付协议，包括主协议，客户退货协议，客户交换协议和客户商家交易争议解决协议。根据SET协议的效率，提出了一种安全分层控制模型，可以根据客户的实际需求选择不同的安全级别进行操作，并对模型的原理和实现进行了分析。