A multi-use unidirectional certificateless proxy re-signature scheme

Proxy re-signature (PRS) allows a semi-trusted proxy served as a translator to transform a signature of delegatee into a signature of delegator on the same message. The heavy overhead of certificate management and the key escrow problem hinder the development of the public key infrastructure-based PRS scheme and the identity (ID)-based PRS, respectively. Featured with the certificate-free and escrow-free properties, certificateless PRS (CL-PRS) has attracted great attention from researchers. However, none of the existing CL-PRS satisfies the multi-use and unidirectional properties. Motivated by the practical applications with long signing chains and the untrusted relationship between two parties, it is desirable to construct a CL-PRS scheme with multi-use and unidirectional properties. This paper proposes the first multi-use unidirectional CL-PRS scheme based on the bilinear pairing. The presented scheme is proved to be secure based on the extended computational Diffie–Hellman assumption under the random oracle model. Performance evaluations demonstrate that our scheme is superior to related works.