Blind Multisignatures for Anonymous Tokens with Decentralized Issuance

Ioanna Karantaidou; Omar Renawi; Foteini Baldimtsi; Nikolaos Kamarinakis; Jonathan Katz; Julian Loss

Paper 2024/1406

Blind Multisignatures for Anonymous Tokens with Decentralized Issuance

Ioanna Karantaidou, George Mason University, New York University

Omar Renawi, CISPA Helmholtz Center for Information Security, Saarland University

Foteini Baldimtsi, George Mason University, Mysten Labs

Nikolaos Kamarinakis, University of Maryland, College Park, Common Prefix

Jonathan Katz, University of Maryland, College Park, Google

Julian Loss, CISPA Helmholtz Center for Information Security

Abstract

We propose the first constructions of anonymous tokens with decentralized issuance. Namely, we consider a dynamic set of signers/issuers; a user can obtain a token from any subset of the signers, which is publicly verifiable and unlinkable to the issuance process. To realize this new primitive we formalize the notion of Blind Multi-Signatures (BMS), which allow a user to interact with multiple signers to obtain a (compact) signature; even if all the signers collude they are unable to link a signature to an interaction with any of them. We then present two BMS constructions, one based on BLS signatures and a second based on discrete logarithms without pairings. We prove security of both our constructions in the Algebraic Group Model. We also provide a proof-of-concept implementation and show that it has low-cost verification, which is the most critical operation in blockchain applications.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Major revision. ACM-CCS 2024
DOI: https://doi.org/10.1145/3658644.3690364
Keywords: Blind Signatures Anonymous tokens Decentralized issuance
Contact author(s): ikaranta @ gmu edu
omar renawi @ cispa de
foteini @ gmu edu
k4m4 @ umd edu
jkatz2 @ gmail com
loss @ cispa de
History: 2024-09-11: revised; 2024-09-09: received; See all versions
Short URL: https://ia.cr/2024/1406
License: CC BY

BibTeX

@misc{cryptoeprint:2024/1406,
      author = {Ioanna Karantaidou and Omar Renawi and Foteini Baldimtsi and Nikolaos Kamarinakis and Jonathan Katz and Julian Loss},
      title = {Blind Multisignatures for Anonymous Tokens with Decentralized Issuance},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1406},
      year = {2024},
      doi = {https://doi.org/10.1145/3658644.3690364},
      url = {https://eprint.iacr.org/2024/1406}
}