A Specification of an Anonymous Credential System Using BBS+ Signatures with Privacy-Preserving Revocation and Device Binding

Christoph Graebnitz; Nicolas Buchmann; Martin Seiffert; Marian Margraf

Paper 2025/824

A Specification of an Anonymous Credential System Using BBS+ Signatures with Privacy-Preserving Revocation and Device Binding

Christoph Graebnitz

Nicolas Buchmann, Fraunhofer Institute for Applied and Integrated Security

Martin Seiffert, Fraunhofer Institute for Applied and Integrated Security

Marian Margraf, Fraunhofer Institute for Applied and Integrated Security

Abstract

Recently, there has been a growing interest in anonymous credentials (ACs) as they can mitigate the risk of personal data being processed by untrusted actors without consent and beyond the user's control. Furthermore, due to the privacy-by-design paradigm of ACs, they can prove possession of personal attributes, such as an authenticated government document containing sensitive personal information, while preserving the privacy of the individual by not actually revealing the data. Typically, AC specifications consider the privacy of individuals during the presentation of an AC, but often neglect privacy-preserving approaches for enhanced security features such as AC non-duplication or AC revocation. To achieve more privacy-friendly enhanced security features of non-duplication and privacy-preserving revocation, an AC can be partially stored on secure, trusted hardware and linked to a status credential that reflects its revocation status. In this paper, we specify an AC system that satisfies the requirements of minimality of information, unlinkability, non-duplication, and privacy-preserving revocation. This is achieved by adapting the hardware binding method of the Direct Anonymous Attestation protocol with the BBS+ short group signatures of Camenisch et al. and combining it with status credentials.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
Keywords: anonymous credentials privacy-preserving revocation device binding bbs+ signature
Contact author(s): christoph graebnitz @ aisec fraunhofer de
nicolas buchmann @ aisec fraunhofer de
martin seiffert @ aisec fraunhofer de
marian margraf @ aisec fraunhofer de
History: 2025-05-09: approved; 2025-05-09: received; See all versions
Short URL: https://ia.cr/2025/824
License: CC BY

BibTeX

@misc{cryptoeprint:2025/824,
      author = {Christoph Graebnitz and Nicolas Buchmann and Martin Seiffert and Marian Margraf},
      title = {A Specification of an Anonymous Credential System Using {BBS}+ Signatures with Privacy-Preserving Revocation and Device Binding},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/824},
      year = {2025},
      url = {https://eprint.iacr.org/2025/824}
}