A Many Valued Representation and Propagation of Trust and Distrust

As the amount of information on the web grows, users may find increasing challenges in trusting and sometimes distrusting sources. One possible aid is to maintain a network of trust between sources. In this paper, we propose to model such a network as an intuitionistic fuzzy relation. This allows to elegantly handle together the problem of ignorance, i.e. not knowing whether to trust or not, and vagueness, i.e. trust as a matter of degree. We pay special attention to deriving trust information through a trusted third party, which becomes especially challenging when distrust is involved.