Towards reliable trust establishment in grid: a pre-evaluating set based reputation evaluation approach

Without reliable trust relationship established between cooperative parties, the paradigm of large-scale resource sharing and cooperative problem solving as envisioned by most will not come true in grid. What´s more, for the scale and openness of grid environment, cooperation often occurs among completely unknown entities, where traditional identity-based trust system obviously cannot work well for its restricted scalability and flexibility. In this paper, we propose a pre-evaluating set based trust model, which resorts to reputation mechanisms for trust establishment. The introduction of the pre-evaluating set is to track an entity´s rating criteria, overcome the prevalent strangeness of grid entities. With this pre-evaluating set, we can reasonably filter out malicious ratings by examining inconsistency between ratings to this set and to real transactions, effectively tune a rater´s bias to cater to the current evaluator´s criteria by interpolation approach and scientifically weight a rater´s rating in aggregation by the introduction of criteria coherent degree which describes the similarity between an entity´s rating criteria and the current evaluator´s.