Abstract
Online reviews are widely used for purchase decisions. Their trustworthiness is limited, however, by fake reviews. Fortunately, opinions from friends in a social network are more reliable but less convenient to obtain. Combining the advantages of online reviews and opinions from friends can be achieved by enabling users to recognize the online reviews originating from their friends. By leveraging buyers ' trust to nearby friends within their social network, it is possible to provide them in some cases with online reviews they can entirely trust. In this paper we present techniques to enable users to recognize the online reviews from their friends in a privacy-preserving manner. Our approach has many applications such as Internet auctions and online gaming. © 2009 IEEE.