Carnegie Mellon University
The problem of determining whether a receiver may safely accept attributes (e.g., identity, credentials, location) of unknown senders in various online social protocols is a special instance of a more general problem of establishing trust in interactive protocols. The authors introduce the notion of interactive trust protocols to illustrate the usefulness of social collateral in reducing the inherent trust asymmetry in large classes of online user interactions. They define a social collateral model that allows receivers to accept attributes from unknown senders based on explicit recommendations received from social relations. They use social collateral as a measure of both social relations and "Tie strength" among individuals to provide different degrees of accountability when accepting attribute information from unknown senders.