Abstract. A group signature scheme allows a group member to sign messages anonymously on behalf of the group. However, in the case of a dispute, the identity of a signature's originator can be revealed (only) by a designated entity. The interactive counterparts of group signatures are identity escrow schemes or group identification scheme with revocable anonymity. This work introduces a new provably secure group signature and a companion identity escrow scheme that are significantly more efficient than the state of the art. In its interactive, identity escrow form, our scheme is proven secure and coalition-resistant under the strong RSA and the decisional Diffie-Hellman assumptions. The security of the noninteractive variant, i.e., the group signature scheme, relies additionally on the Fiat-Shamir heuristic (also known as the random oracle model).
They implement and test the pairing-based group signature scheme (i.e., the BBS scheme proposed by ) and the non-pairing group signature scheme (i.e., the ACJT scheme proposed by REF ).
A Practical and Provably Secure Coalition-Resistant Group Signature Scheme
CRYPTO
Computer Science