Optimization of the MOVA Undeniable Signature Scheme

This article presents optimization results on the recent MOVA undeniable signature scheme presented by Monnerat and Vaudenay at PKC ’04 as well as its generalization proposed at Asiacrypt ’04 which is based on a secret group homomorphism. The original MOVA scheme uses characters on Z∗ n and some additional candidates homomorphisms were proposed with its generalization. We give an overview of the expected performances of the MOVA scheme depending on the group homomorphism. Our optimizations focus on the quartic residue symbol and an homomorphism based on the computation of a discrete logarithm in a hidden subgroup of Z∗ n. We demonstrate that the latter provides a signature generation which is three times faster than RSA. Key words: Undeniable signatures, optimization.

• Type: Conference
• Year: 2005
• Where: MYCRYPT
• Authors: Jean Monnerat, Yvonne Anne Oswald, Serge Vaudenay
• Keywords: Cryptology, Group Homomorphism, MYCRYPT 2005, Undeniable Signature Scheme, Undeniable Signatures