An efficient short certificate-based signature scheme

Abstract

Certificate-based cryptography combines the merits of traditional public key infrastructure (PKI) and identity-based cryptography. It does not have the key escrow problem in identity-based cryptography, and eliminates the certificate revocation problem and third-party queries in traditional PKI. In this paper, we first refine the security model of certificate-based signatures introduced in EuroPKI’07. We then present a short certificate-based signature scheme, which is proven to be existentially unforgeable against adaptive chosen message attacks in the random oracle model. Our scheme requires only one pairing operation (and three pre-computable pairing operations) in signature generation and verification. In addition, the signature size of our scheme is only one group element. To the best of our knowledge, the signature size of our scheme is the shortest and the computational cost is the lowest when compared with other concrete certificate-based signature schemes in the literature. This makes our scheme possess strong applicability in situations with limited bandwidth and power-constrained devices.