A New Certificateless Proxy Re-signature Scheme in the Standard Model

The existing proxy re-signature schemes are mostly constructed in traditional cryptosystems or identity-based cryptosystems. The former has the problem of complexity certificate management and overhead signature verification time, while the latter has the problem of key escrow security. A proxy re-signature scheme without certificates is proposed. The scheme is proved to be existentially unforgeable in standard model and its security can be stipulated as the difficulties of NGBDH and Many-DH assumption.