Almost fully anonymous attribute-based group signatures with verifier-local revocation and member registration from lattice assumptions

Attribute-Based Group Signature (ABGS) schemes permit any group member with required attributes to generate signatures for the sake of the group anonymously. Even though existing ABGS schemes with Verifier-local Revocation (VLR) method facilitate efficient user and attribute revocation, they cannot achieve stronger security for the users and user attributes. In this paper, we present a new approach to overcome this weakness delivering a new ABGS scheme with VLR that achieves stronger security, almost full anonymity, for both users and their attributes. We construct our scheme from lattices as lattice cryptography is quantum resist. Moreover, we present a simple member joining protocol and a new zero-knowledge argument system that supports the new scheme. Finally, we prove that the proposed scheme meets the security requirements of almost full anonymity, traceability, and non-frameability.