Seminario: "Canonical Lifting for Group-Action Protocols: Beyond Ring Signatures?" - Leonardo Errati

ALPEC - Algebraic computation and Privacy Enhancing Cryptography - Summer School

Dipartimento di Matematica
Università di Trento
Polo Ferrari - Povo 1, Via Sommarive, 5, 38123 Trento.

Canonical Lifting for Group-Action Protocols: Beyond Ring Signatures?
Leonardo Errati (Politecnico di Torino)

Abstract: Canonical liftings were introduced in a recent preprint as a means to compress group-action-based sigma protocols. They generalise existing techniques, such as the canonical forms used in LESS, and thus are inherently a compression argument; however, under some hypotheses, they preserve the hardness of the underlying group-action.
We show how they can be used to produce a (linkable) ring signature, instantiated on linear code equivalence as CE(Le)ReS. Can they construct other primitives, such as blind signatures? What happens if we instantiate them on, e.g., the group actions underlying lattices and isogenies?