Paper 2022/004 Original: eprint.iacr.org/2022/004 ↗
Publicly verifiable anonymous tokens with private metadata bit
Abstract
We present a new construction for publicly verifiable anonymous tokens with private metadata. This primitive enables an issuer to generate an anonymous authentication token for a user while embedding a single private metadata bit. The token can be publicly verified, while the value of the private metadata is only accessible to the party holding the secret issuing key and remains hidden to any other party, even to the user. The security properties of this primitive also include unforgeability, which guarantees that only the issuer can generate new valid tokens, and unlinkability that guarantees that tokens issued with the same private metadata bit are indistinguishable. Our anonymous tokens scheme builds on the top of blind Schnorr signatures. We analyze its security in the algebraic group model and prove its security under the modified ROS assumption, one-more discrete logarithm, and decisional Diffie-Hellman assumptions.
Metadata
- Available format(s)
PDF- Category
- Public-key cryptography
- Publication info
- Preprint.
- History
- 2022-01-02: last updated
- 2022-01-01: published
- Short URL
- https://ia.cr/2022/004
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2022/004,
author = {Fabrice Benhamouda and Tancrède Lepoint and Michele Orrù and Mariana Raykova},
title = {Publicly verifiable anonymous tokens with private metadata bit},
howpublished = {Cryptology {ePrint} Archive, Paper 2022/004},
year = {2022},
url = {https://eprint.iacr.org/2022/004}
}