Paper 2025/161

Secure Showing of Partial Attributes

Foteini Baldimtsi, George Mason University, Mysten Labs
Julia Kastner, Centrum Wiskunde & Informatica
Julian Loss, Helmholtz Center for Information Security
Omar Renawi, Helmholtz Center for Information Security, Saarland University
Abstract

Anonymous Attribute-Based Credentials (ABCs) allow users to prove possession of attributes while adhering to various authentication policies and without revealing unnecessary information. Single-use ABCs are particularly appealing for their lightweight nature and practical efficiency. These credentials are typically built using blind signatures, with Anonymous Credentials Light (ACL) being one of the most prominent schemes in the literature. However, the security properties of single-use ABCs, especially their secure showing property, have not been fully explored, and prior definitions and corresponding security proofs fail to address scenarios involving partial attribute disclosure effectively. In this work, we propose a stronger secure showing definition that ensures robust security even under selective attribute revelation. Our definition extends the winning condition of the existing secure showing experiment by adding various constraints on the subsets of opened attributes. We show how to represent this winning condition as a matching problem in a suitable bipartite graph, thus allowing for it to be verified efficiently. We then prove that ACL satisfies our strong secure showing notion without any modification. Finally, we define double-spending prevention for single-use ABCs, and show how ACL satisfies the definition.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
Blind SignaturesAnonymous Credentials
Contact author(s)
foteini @ gmu edu
julia kastner @ cwi nl
loss @ cispa de
omar renawi @ cispa de
History
2025-02-05: revised
2025-02-03: received
See all versions
Short URL
https://ia.cr/2025/161
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/161,
      author = {Foteini Baldimtsi and Julia Kastner and Julian Loss and Omar Renawi},
      title = {Secure Showing of Partial Attributes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/161},
      year = {2025},
      url = {https://eprint.iacr.org/2025/161}
}
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