Title
Multimodal Private Signatures
Publication Name
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
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.
Open Access Status
This publication may be available as open access
Volume
13508 LNCS
First Page
792
Last Page
822
Funding Number
DP200100144
Funding Sponsor
Australian Research Council