Punishing manipulation attacks in mobile agent systems

Mobile agents are software entities consisting of code, data and state that can migrate autonomously from host to host performing some actions on behalf of a user. Unfortunately, security issues restrict the use of mobile agents, despite the benefits. The protection of mobile agents against the attacks of malicious hosts is considered the most difficult security problem to solve in mobile agent systems. Previously, the mobile agent watermarking approach (MAW) was presented as a new attack detection technique to aid solving the problem of malicious hosts. That approach was based on embedding a fixed watermark into the mobile agent. Some improvements are now introduced to MAW. Instead of a fixed watermark, the origin host embeds a watermark that can change dynamically during execution. In each host, the marked code creates a data container where the watermark is transferred and the results are hidden. When the agent returns home, the origin host verifies the execution integrity by applying a set of integrity rules to the containers. The paper also explains how MAW can be used to punish malicious hosts by using a trusted third party, the host revocation authority.