Cryptographic Traces for Mobile Agents

Mobile code systems are technologies that allow applications to move their code, and possibly the corresponding state, among the nodes of a wide-area network. Code mobility is a exible and powerful mechanism that can be exploited to build distributed applications in an Internet scale. At the same time, the ability to move code to and from remote hosts introduces serious security issues. These issues include authentication of the parties involved and protection of the hosts from malicious code. However, the most diicult task is to protect mobile code against attacks coming from hosts. This paper presents a mechanism based on execution tracing and cryptography that allows one to detect attacks against code, state, and execution ow of mobile software components.