SURVEY OF TRUST MODELS IN DIFFERENT NETWORK DOMAINS

This paper introduces the security and trust concepts in wireless sensor networks and explains thedifference between them, stating that even though both terms are used interchangeably when defining asecure system, they are not the same. The difference between reputation and trust is also explained, highlighting that reputation partially affects trust. A survey of trust and reputation systems in variousdomains is conducted, with more details given to models in ad-hoc and sensor networks as they are closelyrelated to each other and to our research interests. The methodologies used to model trust and theirreferences are presented. The factors affecting trust updating are summarised and some examples of thesystems in which these factors have been implemented are given. The survey states that, even thoughresearchers have started to explore the issue of trust in wireless sensor networks, they are still examiningthe trust associated with routing messages between nodes (binary events). However, wireless sensornetworks are mainly deployed to monitor events and report data, both continuous and discrete. This leadsto the development of new trust models addressing the continuous data issue and also to combine the datatrust and the communication trust to infer the total trust.