An Uncertainty Enhanced Trust Evolution Strategy for e-Science

Resources shared in e-Science have critical requirements on security. Thus subjective trust management is essential to guarantee users' collaborations and communications on such a promising infrastructure. As an important nature of subjective trust, uncertainty should be preserved and exhibited in trust definition, representation and evolution. Consider the drawbacks of existing mechanisms based on random mathematics and fuzzy theory, this paper designs an uncertainty enhanced trust evolution strategy based on cloud model theory. We define subjective trust as trust cloud. Then we propose new algorithms to propagate, aggregate and update trust. Furthermore, based on the concept of similar cloud, a method to assess trust level is put forward. The simulation results show the effectiveness, rationality and efficiency of our proposed strategy.