A Hybrid Trust and Trade Service for Mobile Collaborative Computing

Allowing a mobile device to provide a service to the neighbouring peers carries non-negligible risks, of which confidentiality, privacy and selfishness are good examples. To discourage selfishness, two approaches are typically taken: i) in trade based systems, devices agree on a retribution for the execution of a task, ii) in trust based systems rogue devices are detected and announced by their peers. We show that in some scenarios found in wireless mobile networks both present sub-optimal results. The paper describes and evaluates a hybrid service, combining trade and trust-based characteristics. The service suits well privacy requirements as it assumes and encourages users to frequently change their pseudonyms. The paper shows that the service detects several misbehaving approaches, even without requiring interacting devices to be connected to the Internet.