### Decentralized reputation

Tassos Dimitriou

##### Abstract

Reputation systems constitute one of the few workable mechanisms for distributed applications in which users can be made accountable for their actions. By collecting user experiences in reputation profiles, participants are encouraged to interact more with well-behaving peers hence better online behavior is motivated. In this work, we develop a privacy-preserving reputation scheme for collaborative systems such as P2P networks in which peers can represent themselves with different pseudonyms when interacting with others. All these pseudonyms, however, are bound to the same reputation token, allowing honest peers to maintain their good record, even when switching to a new pseudonym, while at the same time preventing malicious peers from making a fresh start. Our system is truly decentralized. Using an append-only distributed ledger such as Bitcoin’s blockchain, we show how participants can make anonymous yet verifiable assertions about their own reputation. In particular, reputation can be demonstrated and updated effectively using efficient zkSNARK proofs. The system maintains soundness, peer-pseudonym unlinkability as well as unlinkability among pseudonyms of the same peer. We formally prove these properties and we evaluate the efficiency of the various operations envisioned in our scheme.

Note: Improved presentation regarding the registration authority. Even this role now is completely decentralized.

Available format(s)
Category
Applications
Publication info
Preprint. MINOR revision.
Keywords
ReputationDecentralizationPrivacyPeer-to-peer networksCollaborative systemsBlockchainzkSNARKs
Contact author(s)
tassos dimitriou @ ieee org
History
2020-09-29: revised
See all versions
Short URL
https://ia.cr/2020/761

CC BY

BibTeX

@misc{cryptoeprint:2020/761,
author = {Tassos Dimitriou},
title = {Decentralized reputation},
howpublished = {Cryptology ePrint Archive, Paper 2020/761},
year = {2020},
note = {\url{https://eprint.iacr.org/2020/761}},
url = {https://eprint.iacr.org/2020/761}
}

Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.