Paper 2024/2013

Crescent: Stronger Privacy for Existing Credentials

Christian Paquin, Microsoft Research
Guru-Vamsi Policharla, University of California, Berkeley
Greg Zaverucha, Microsoft Research
Abstract

We describe Crescent, a construction and implementation of privacy-preserving credentials. The system works by upgrading the privacy features of existing credentials, such as JSON Web Tokens (JWTs) and Mobile Driver’s License (mDL) and as such does not require a new party to issue credentials. By using zero-knowledge proofs of possession of these credentials, we can add privacy features such as selective disclosure and unlinkability, without help from credential issuers. The system has practical performance, offering fast proof generation and verification times (tens of milliseconds) after a once-per-credential setup phase. We give demos for two practical scenarios, proof of employment for benefits eligibility (based on an employer-issued JWT), and online age verification (based on an mDL). We provide an open-source implementation to enable further research and experimentation. This paper is an early draft describing our work, aiming to include enough material to describe the functionality, and some details of the internals of our new library, available at https://github.com/microsoft/crescent-credentials.

Metadata
Available format(s)
PDF
Category
Applications
Publication info
Preprint.
Keywords
PrivacyAnonymous Credentialszero-knowledge proofs
Contact author(s)
cpaquin @ microsoft com
guruvamsi policharla @ gmail com
gregz @ microsoft com
History
2024-12-13: approved
2024-12-13: received
See all versions
Short URL
https://ia.cr/2024/2013
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2024/2013,
      author = {Christian Paquin and Guru-Vamsi Policharla and Greg Zaverucha},
      title = {Crescent: Stronger Privacy for Existing Credentials},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/2013},
      year = {2024},
      url = {https://eprint.iacr.org/2024/2013}
}
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