Modern access control models, developed for protecting data from accesses across the Internet, require to verify the identity of users in order to make sure that users have the required permissions for accessing the data. User's identity consists of data, referred to as identity attributes, that...

Trust negotiation is a promising approach for establishing trust in open systems, in which sensitive interactions may often occur between entities with no prior knowledge of each other. Although, to date several trust negotiation systems have been proposed, none of them fully address the problem...