A Novel Subjective Logic for Trust Management

A novel subjective logic based on the Dezert-Smarandache theory is proposed. The original subjective logic based on the Dempster-Shafer theory of evidence is an extension of the standard logic and probability calculus. The subjective logic is a framework of uncertain reasoning, and it is widely studied because of its successful application to trust management. But the elementary elements of the frame of discernment are assumed to be exclusive, which is a strong constraint. The new subjective logic based on the framework of the Dezert-Smarandache theory, which is able to handle both uncertain and paradoxical information, is an extension of the subjective logic by overcoming this strong constraint. In addition, the logical operators of the new subjective logic are inferred and proved to be the extension of the logical operators of the subjective logic. Two evidential operators including discounting operator and consensus operator are defined for trust recommendation and accumulation. The discounting operator of the new subjective logic is more flexible. The shortcomings of the consensus operator of the original subjective logic are presented. A consensus operator of the new subjective logic is proposed which can overcome these shortcomings. Finally, the experiment shows that the computational complexity of the novel subjective logic is acceptable.