Abstract:This paper presents a strongly secure certificateless signature scheme without pairings, which is existentially unforgeable against adaptive chosen message and ID attacks. The complete security proof is given under random oracle model, assuming that the discrete logarithm problem is intractable. The scheme is more computationally efficient than others built from pairings,as there is no heavily cost pairing operation in this scheme. In addition, a security analysis is presented for Wang H G’s pairing-free certificateless public key signature, and the results show that the scheme is insecure with a concrete attack method.