A Trustless Privacy-Preserving Reputation System

• Published in: ICT Systems Security and Privacy Protection Vol. 471; pp. 398 - 411
• Main Authors: Schaub, Alexander, Bazin, Rémi, Hasan, Omar, Brunie, Lionel
• Format: Book Chapter
• Language: English
• Published: Switzerland Springer International Publishing AG 2016; Springer International Publishing
• Series: IFIP Advances in Information and Communication Technology
• Subjects: Blind Signature; Certification Authority; Computer security; Reputation System; Service Provider; Trusted Third Party
• ISBN: 3319336290; 9783319336299
• ISSN: 1868-4238; 1868-422X; 1868-422X
• DOI: 10.1007/978-3-319-33630-5_27

Reputation systems are crucial for distributed applications in which users have to be made accountable for their actions, such as e-commerce websites. However, existing systems often disclose the identity of the raters, which might deter honest users from submitting reviews out of fear of retaliation from the ratees. While many privacy-preserving reputation systems have been proposed, we observe that none of them is simultaneously truly decentralized, trustless, and suitable for real world usage in, for example, e-commerce applications. In this paper, we present a blockchain based decentralized privacy-preserving reputation system. We demonstrate that our system provides correctness and security while eliminating the need for users to trust any third parties or even fellow users.