A Trust Based System for Enhanced Spam Filtering

The effectiveness of current anti-spam systems is limited by the ability of spammers to adapt to filtering techniques and the lack of incentive for mail servers to filter outgoing spam. A new approach, based on decentralised trust management, is described in this paper. An architecture and protocol, called TOPAS (Trust Overlay Protocol for Anti Spam), are presented. Each mail server records trust measures relating to each other mail server of which it is aware. Trust by one mail server in another is influenced by direct experience as well as recommendations issued by collaborating mail servers.