A security protocol for mobile agents based upon the cooperation of sedentary agents

Despite its many benefits, mobile agent technology results in significant security threats from agents and hosts. This paper presents a protocol which protects mobile agents from malicious hosts. This protocol combines four concepts: the cooperation between a mobile agent and a sedentary agent; the reference execution (reliable platforms which shelter our cooperating sedentary agents); the cryptography and the digital signature to ensure safe inter-agent communication and time-limited execution (timeout). A dynamic approach which makes use of a timer to make it possible to detect a mobile agent's code re-execution was used. The attack on agent permanent modification was also dealt with. Moreover, the protocol is sufficiently robust so that it is durable and fault tolerant.