Group Signatures: Provable Security, Efficient Constructions and Anonymity from Trapdoor-Holders.
Aggelos Kiayias, Moti M. Yung · 2004
To date, a group signature construction which is both efficient and proven secure in a formal model has not been suggested. In this work we give the first such construction. To this end we present a new formal model for group signatures capturing the state-of-the-art requirements in the area. We then construct an efficient scheme and prove its security. Our methods require novel cryptographic constructs and new number-theoretic machinery for arguing security over the group of quadratic residues modulo a composite when its factorization is known. Along the way, we unveil properties which go beyond the state-of-the-art-scheme [Ateniese et al.2000] and reveal subtle points regarding the assumptions and requirements that underly efficient group signature schemes.