%0 Conference Paper
%B Network Computing and Applications, 2009. NCA 2009. Eighth IEEE International Symposium on
%D 2009
%T A Collusion-Resistant Distributed Scalar Product Protocol with Application to Privacy-Preserving Computation of Trust
%A Melchor, C.A.
%A Ait-Salem, B.
%A Gaborit, P.
%K collaboration
%K collusion-resistant distributed protocol
%K Computer applications
%K computer networks
%K cryptographic protocols
%K cryptography
%K data privacy
%K distributed computing
%K homorphic encryption computation
%K Laboratories
%K Portable media players
%K privacy-preserving computation
%K Privacy-preserving computation of trust
%K private multiparty summation protocol
%K scalar product protocol
%K secure multi-party computation
%K Secure scalar product
%K security
%K Superposed sending.
%K Telephony
%K trust computation
%X Private scalar product protocols have proved to be interesting in various applications such as data mining, data integration, trust computing, etc. In 2007, Yao et al. proposed a distributed scalar product protocol with application to privacy-preserving computation of trust [1]. This protocol is split in two phases: an homorphic encryption computation; and a private multi-party summation protocol. The summation protocol has two drawbacks: first, it generates a non-negligible communication overhead; and second, it introduces a security flaw. The contribution of this present paper is two-fold. We first prove that the protocol of [1] is not secure in the semi-honest model by showing that it is not resistant to collusion attacks and we give an example of a collusion attack, with only four participants. Second, we propose to use a superposed sending round as an alternative to the multi-party summation protocol, which results in better security properties and in a reduction of the communication costs. In particular, regarding security, we show that the previous scheme was vulnerable to collusions of three users whereas in our proposal we can t isin [1..n - 1] and define a protocol resisting to collusions of up to t users.
%B Network Computing and Applications, 2009. NCA 2009. Eighth IEEE International Symposium on
%8 July
%G eng
%R 10.1109/NCA.2009.48