Efficient certificate-based signature and its aggregation

The certificate-based cryptography is proposed to eliminate the key escrow problem of ID-based public key cryptography and simplify certificate management procedures of traditional public key infrastructure (PKI) in the same time. Since its invention, many certificate-based signature have been proposed. However, the existing schemes either only support partial aggregateability, or require a pre-negotiated one-time-use nonce. To solve this problem, in this paper, we propose a new certificate-based signature scheme where signatures on the same message signed by different users can be aggregated into a single signature without the pre-negotiated one-time-use nonce. Furthermore, verification in our proposal only involves four pairing operations. Our proposed certificate-based (aggregate) signature scheme can be considered as the combination of Gentry-Ramzan identity-based aggregate signature scheme and Boneh-Lynn-Shacham short signature scheme. Similar to their schemes, our proposal can be also proven secure in the random oracle model based on the computational Diffie-Hellman assumption.