A Revocable Certificateless Signature Scheme

Abstract

Certificateless public key cryptography (CLPKC), with properties of no key escrow and no certificate, has received a lot of attention since its invention. However, how to revoke a user in certificateless cryptosystem still remains a problem: the existing solutions are not practical for use due to either a costly mediator or enormous computation (secret channel). In this paper, we present a new approach to solve the revocation problem in CLPKC, by giving a concrete revocable certificateless signature scheme. The new scheme is more efficient than the existing solutions and is provably secure under the Computational Diffie-Hellman assumption.