Multi-contextual Trust Model for Multi-Agent Systems

trust, multi-context trust, distributed multi- agent systems, HMTC

This paper deals with trust modelling for distributed systems especially to multi-context trust modelling for multi- agent distributed systems. There exists many trust and reputation models but most of them do not dealt with the multi-context property of trust or reputation. Therefore, the main focus of this thesis is on analysis of multi- context trust based models and provides main assumptions for new fully multi-contextual trust model on the bases of them. The main part of this thesis is in providing new formal multi-context trust model which are able to build, update and maintain trust value for different aspects (contexts) of the single entity in the multi-agent system. In our proposal, trust value can be built on the bases of direct interactions or on the bases on recommendations and reputation. Moreover we assume that some context of one agent is not fully independent and on the bases of trust about one of them we are able to infer trust to another's. Main contribution of this new model is increasing the efficiency in agent decision making in terms of optimal partner selection for interactions. Proposed model was verified by implementing prototype of multi-agent system when trust was used for agents' decision making and acting.