Undeniable Signatures Based on Characters: How to Sign with One Bit

We present a new undeniable signature scheme which is based on the computation of characters. Our signature scheme offers the advantage of having an arbitrarily short signature. Its asymptotic complexity is attractive: the asymptotic complexity of all algorithms (even the key setup) are quadratic in the size of the modulus n in bits when the other parameters are fixed. The practical complexity can be quite low depending on parameter and variant choices. We present also a proof of security of our scheme containing the standard security requirements of an undeniable signature. Key words: Undeniable Signatures, Residue Characters.

• Type: Conference
• Year: 2004
• Where: PKC
• Authors: Jean Monnerat, Serge Vaudenay
• Keywords: Cryptography, PKC 2004, Signature Scheme, Undeniable Signature Scheme, Undeniable Signatures