Privacy-Preserving Auditing for Attribute-Based Credentials

Jan Camenisch; Anja Lehmann; Gregory Neven; Alfredo Rial

Paper 2014/468

Privacy-Preserving Auditing for Attribute-Based Credentials

Jan Camenisch, Anja Lehmann, Gregory Neven, and Alfredo Rial

Abstract

Privacy-enhancing attribute-based credentials (PABCs) allow users to authenticate to verifiers in a data-minimizing way, in the sense that users are unlinkable between authentications and only disclose those attributes from their credentials that are relevant to the verifier. We propose a practical scheme to apply the same data minimization principle when the verifiers’ authentication logs are subjected to external audits. Namely, we propose an extended PABC scheme where the verifier can further remove attributes from presentation tokens before handing them to an auditor, while preserving the verifiability of the audited tokens. We present a generic construction based on a signature, a signature of knowledge and a trapdoor commitment scheme, prove it secure in the universal composability framework, and give efficient instantiations based on the strong RSA and Decision Composite Residuosity (DCR) assumptions in the random-oracle model.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Major revision. ESORICS 2014
Keywords: privacy-enhancing credentials data minimization auditing
Contact author(s): anj @ zurich ibm com
History: 2014-06-21: received
Short URL: https://ia.cr/2014/468
License: CC BY

BibTeX

@misc{cryptoeprint:2014/468,
      author = {Jan Camenisch and Anja Lehmann and Gregory Neven and Alfredo Rial},
      title = {Privacy-Preserving Auditing for Attribute-Based Credentials},
      howpublished = {Cryptology {ePrint} Archive, Paper 2014/468},
      year = {2014},
      url = {https://eprint.iacr.org/2014/468}
}