An Efficient Threshold Signature Scheme Without Random Oracles

We present a robust threshold signature scheme which is provably secure without random oracles under the computational Diffie-Hellman assumption. Our construction derives from a novel application of the recent signature scheme due to Waters. Compared with Wang et al.'s threshold signature scheme without random oracles, the signing procedure of our scheme is much more efficient in terms of communication and computation. In fact, our threshold signature scheme's efficiency is comparable to Boldyreva's threshold signature scheme which is provably secure in the random oracle model(ROM).