Secure Two-Party Computation in Social Cloud Based on Reputation

Parties are expected to be cooperative such that some tasks, e.g. Two-party computation in social cloud, become much easier. It is well known that reputation is an important property to promote cooperation among parties in game theory. Therefore, we consider the effect of reputation when parties interact in social cloud to find a new way realizing mutual cooperation. More specifically, parities in the social cloud are rational who value their reputation. Cooperation can boost their reputation, so they have incentives to cooperate with others such that they may get a higher utility. The basic idea of this paper is to add reputation deriving from social cloudas part of the utility. That is, we describe the architecture and interaction between two rational parties in the social cloud, where two parties receive their opponent´s trust or reputation from the social cloud. The computation of trust and reputation is finished in the social cloud. Finally, we prove that given proper parameters in rational secure two-party computation (rational STPC), it is possible to complete the computation in just one round in the second stage of the protocol.