The self-blindable U-Prove scheme from FC'14 is forgeable

Eric Verheul; Sietse Ringers; Jaap-Henk Hoepman

Paper 2015/725

The self-blindable U-Prove scheme from FC'14 is forgeable

Eric Verheul, Sietse Ringers, and Jaap-Henk Hoepman

Abstract

Recently an unlinkable version of the U-Prove attribute-based credential scheme was proposed at Financial Crypto '14. Unfortunately, the new scheme is forgeable: if sufficiently many users work together then they can construct new credentials, containing any set of attributes of their choice, without any involvement of the issuer. In this note we show how they can achieve this and we point out the error in the unforgeability proof.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Financial Cryptography 2016
Keywords: anonymous credentials attribute-based credentials
Contact author(s): s ringers @ rug nl
History: 2016-02-10: last of 2 revisions; 2015-07-21: received; See all versions
Short URL: https://ia.cr/2015/725
License: CC BY

BibTeX

@misc{cryptoeprint:2015/725,
      author = {Eric Verheul and Sietse Ringers and Jaap-Henk Hoepman},
      title = {The self-blindable U-Prove scheme from {FC}'14 is forgeable},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/725},
      year = {2015},
      url = {https://eprint.iacr.org/2015/725}
}