Publication Type

Conference Proceeding Article

Version

publishedVersion

Publication Date

8-2022

Abstract

We introduce Multimodal Private Signature (MPS) - an anonymous signature system that offers a novel accountability feature: it allows a designated opening authority to learn some partial information op about the signer’s identity id, and nothing beyond. Such partial information can flexibly be defined as op = id (as in group signatures), or as op = 0 (like in ring signatures), or more generally, as op = Gj (id), where Gj (·) is a certain disclosing function. Importantly, the value of op is known in advance by the signer, and hence, the latter can decide whether she/he wants to disclose that piece of information. The concept of MPS significantly generalizes the notion of tracing in traditional anonymity-oriented signature primitives, and can enable various new and appealing privacy-preserving applications. We formalize the definitions and security requirements for MPS. We next present a generic construction to demonstrate the feasibility of designing MPS in a modular manner and from commonly used cryptographic building blocks (ordinary signatures, public-key encryption and NIZKs). We also provide an efficient construction in the standard model based on pairings, and a lattice-based construction in the random oracle model.

Keywords

new models, anonymous authentications, accountability, fine-grained information disclosure, modular constructions, zero-knowledge, lattices, pairings

Discipline

Databases and Information Systems | Information Security

Research Areas

Cybersecurity

Publication

Advances in Cryptology CRYPTO 2022: 42nd Annual International Conference, Santa Barbara, CA, August 15-18: Proceedings

Volume

13508

First Page

792

Last Page

822

ISBN

9783031159794

Identifier

10.1007/978-3-031-15979-4_27

Publisher

Springer

City or Country

Cham

Copyright Owner and License

Publisher

Additional URL

https://doi.org/10.1007/978-3-031-15979-4_27

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