Summary: In this paper, we propose the security notion of certificate-based signature that uses the same parameters and certificate revocation strategy as the encryption scheme presented at Eurocrypt 2003 by C. Gentry [“Certificate-based encryption and the certificate revocation problem”, Lect. Notes Comput. Sci. 2656, 272–293 (2003; Zbl 1037.68533)]. Certificate-based signature preserves advantages of certificate-based encryption, such as implicit certification and no private key escrow. We present concrete certificate-based signature schemes derived from pairings on elliptic curves and prove their security in the random oracle model assuming that the underlying group is GDH. Additionally, we propose a concrete delegation-by-certificate proxy signature scheme which is derived from a certificate-based signature scheme after simple modifications. Our proxy scheme is provably secure in the random oracle model under the security notion defined by Boldyreva, Palacio and Warinschi.
For the entire collection see [Zbl 1049.94004].