On the Design of a New Trust Model for Mobile Agent Security

Recently, the notion of trust has been recognized as an important aspect of the mobile agent security. However, the current research on trust models focuses only on the hard trust relationships that are usually established via cryptographic mechanisms assuming the availability of Trusted Third Parties (TTPs) and cryptographic protocols for trust verification. We argue that in order to harness the benefits of open network operations securely, the above assumptions need to be relaxed. Thus it is necessary to build a trust model that can be extended beyond the reliance of cryptography based protocols and TTPs, and is capable of managing soft trust relationships in addition to the hard ones in mobile agent systems. We propose a new trust model which provides solutions to meet the above requirements with hybrid trust mechanisms. We analyze the properties of the new trust model and show how they can help improve the effectiveness of hard and soft trust and thus raise the security levels of mobile agent systems.