Trust Management

Volume 238 of the series IFIP International Federation for Information Processing pp 1-16

Private Distributed Scalar Product Protocol With Application To Privacy-Preserving Computation of Trust

  • Danfeng YaoAffiliated withDepartment of Computer Science, Brown University
  • , Roberto TamassiaAffiliated withDepartment of Computer Science, Brown University
  • , Seth ProctorAffiliated withSun Microsystems Laboratories


In this paper, we first present a private distributed scalar product protocol that can be used for obtaining trust values from private recommendations. Our protocol allows Alice to infer the trustworthiness of Bob based on what Alice’s friends think about Bob and Alice’s confidence in her friends. In addition, the private information of Alice and her friends are not revealed during the computation. We also propose a credential-based trust model where the trustworthiness of a user is computed based on his or her affiliations and role assignments. The trust model is simple to compute, yet it is scalable as it classifies large groups of users

Key words

Private multi-party computation trust management location privacy