本文主要讨论保护移动代理免受恶意主机攻击的问题.在指出现有的基于“加密函数”的移动代理保护方法不足的同时作者提出了一种基于可信任元素的安全代理保护模型.这种可信任元素不同于可信任硬件如智能卡和协处理器,它是一种基于加密电路构造的第三方服务称为可信任服务.文中给出了移动代理计算的形式化描述,并说明了纯软件保护方法是不可行的,在介绍完加密电路构造方法后给出了基本模型来说明如何借助于可信任服务实现安全性,并对模型进一步扩充,最后给出应用该模型的一个实例分析.
As a new technology, mobile agent shows a wide application in the field of network technology. However, security has been one of the crucial problems in the employment of mobile agents. In order to protect mobile agent against malicious hosts, some approaches have been proposed in the literature. A new protection model based on a trusted element is presented in this paper. The trusted element, which differs from traditional trusted hardware such as smart card or co-processor, offers a third party service based on an encrypted circuit construction. Procedure of constructing encrypted circuit is introduced and the way to use the trusted service to protect mobile agent is also described. An application example is given to show how to use the new model at the end of the paper.