Certificateless Signatures with Message Recovery

Abstract

In traditional digital signature systems, a trusted third party (TTP) is required in order to issue a digital certificate. The certificate is to assure that the public key actually belongs to the person of the signature. The management of certificates including revocation, storage and distribution is considered to be costly. ID-based signatures do not need a certificate but has the key escrow problem. In 2003, the concept of certificateless signature scheme was introduced. It successfully removed the necessity of certificates and the key escrow problem. On the other hand, a digital signature with message recovery is a signature that the message itself is not required to be transmitted together with the signature. It has the advantage of small data size of communication. In this paper, a certificateless signature with message recovery is proposed. It inherits both the advantages of certificateless signatures and signatures providing message recovery. The performance of our scheme is compared with other schemes which shows that our scheme is quite efficient. We emphasize that this is the first work that proposing the certificateless signatures with message recovery.