Privacy preserving online reputation systems

Abstract

Reputation systems evolve as a mechanism to build trust in dynamic electronic societies. However, they are also a danger to privacy because they monitor a user's behavior. At the same time reputation systems offer the possibility to limit the information a user has to give away during a transaction to ensure accountablity. Privacy preserving reputation systems solve the conflict between anonymity and accountability. This paper examines privacy problems of current reputation systems and classifies them with respect to the location of stored information. Requirements for reputation systems that provide privacy protection are derived from this analysis. As result a new privacy preserving online reputation system is presented that uses locally stored coins to represent reputation information. © 2004 by International Federation for Information Processing.