Paper 2020/450

The Landscape of Pointcheval-Sanders Signatures: Mapping to Polynomial-Based Signatures and Beyond

Kristian L. McDonald

Abstract

Pointcheval-Sanders (PS) signatures are well-studied in the literature and have found use within e.g. threshold credential schemes and redactable anonymous credential schemes. The present work leverages a mapping between PS signatures and a related class of polynomial-based signatures to construct multiple new signature/credential schemes. Specifically, new protocols for multi-message signatures, sequential aggregate signatures, signatures for message commitments, redactable signatures, and unlinkable redactable signatures are presented. A redactable anonymous credential scheme is also constructed. All original protocols employ constant-sized secret keys rather than linear-sized (in the number of messages/attributes). Security properties of the new protocols are analysed and a general discussion of security properties for both PS signatures and the new schemes is provided.