Paper 2007/196

An Efficient Certificateless Signature Scheme

Rafael Castro and Ricardo Dahab

Abstract

In this paper we present a certificateless signature (CLS) scheme secure in the Random Oracle Model. This scheme requires no pairing computations for signature generation and only two for signature verification. As far as we know, this is the only CLS scheme to require less than four pairing computations on signature verification.

Note: We found a flaw on the security reductions that forces additional computations to be done on the verification process. As a consequence, any efficiency gains believed to exist are lost.