Computing multi-party trust privately: In O(n) time units sending one (possibly large) message at a time

Shlomi Dolev, Niv Gilboa, Marina Kopeetsky

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

9 Scopus citations


Schemes for multi-party trust computation are presented. The schemes do not make use of a Trusted Authority. The schemes are more efficient than previous schemes by the number of messages exchanged which is proportional to the number of participants rather than to a quadratic number of the participants. We note that in our schemes the length of each message may be larger than the message length of previous schemes. The calculation of a trust, in a specific user by a group of community members, starts upon a request of an initiating user. The trust computation is provided in a completely distributed manner, while each user calculates its trust value privately. Given a community C and its members (users) U1, ..., Un, we present computationally secure schemes for trust computation. The first Accumulated Protocol AP computes the average trust in a specific user Ut upon the trust evaluation request initiated by a user Un. The exact trust values of each queried user are not disclosed to Un. The next Weighted Accumulated protocol WAP generates the average weighted trust in a specific user Ut taking into consideration the unrevealed trust that Un has in each user participating in the trust process evaluation. We extend our schemes to the case when the initiating user Un can be compromised by the adversary, and we introduce the Multiple Private Keys M P K P and the Multiple Private Keys Weighted M P W P protocols for computing average unweighted and weighted trust, respectively. The computation of all our algorithms requires the transmission of O(n) (possibly large) messages.

Original languageEnglish
Title of host publicationAPPLIED COMPUTING 2010 - The 25th Annual ACM Symposium on Applied Computing
Number of pages6
StatePublished - 23 Jul 2010
Event25th Annual ACM Symposium on Applied Computing, SAC 2010 - Sierre, Switzerland
Duration: 22 Mar 201026 Mar 2010

Publication series

NameProceedings of the ACM Symposium on Applied Computing


Conference25th Annual ACM Symposium on Applied Computing, SAC 2010

ASJC Scopus subject areas

  • Software

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