Efficient Group Signatures with Designated Traceability over Openers’ Attributes from Lattices

• Published in: International Journal of Networking and Computing Vol. 15; no. 2; pp. 153 - 181
• Main Authors: Anada, Hiroaki, Fukumitsu, Masayuki, Hasegawa, Shingo
• Format: Journal Article
• Language: English
• Published: IJNC Editorial Committee 2025
• Subjects: group signature; lattices; openers; attributes
• ISSN: 2185-2839; 2185-2847; 2185-2847
• DOI: 10.15803/ijnc.15.2_153

The group signature with designated traceability (GSdT) is a kind of group signatures (GS) which aim to restrict the opening authority of the group manager; by setting an access structure over openers’ attributes at the signing, a signer is able to control openers who can open the signature. A generic construction of GSdT was given when the notion was introduced, then a pairing-based construction and a symmetric-key-based one were presented. Nonetheless, it remains open whether a post-quantum GSdT with full anonymity can be truly constructed.In this paper, we give a lattice-based GSdT scheme that has full anonymity for the first time. In our construction, the lattice-based ciphertext-policy attribute-based encryption (CPABE) by Tsabary and the lattice-based group signatures (GS) by Libert et al. are employed. The CP-ABE is based on the Regev public-key encryption, while the GS uses a non-interactive zero-knowledge proof to prove the correctness of the encryption in the signing process. Based on the compatibility, we combine and modify them to build up a GSdT scheme.