Security Mediated Certificateless Signatures Without Pairing

Security-mediated certificateless (SMC) signature provides a method for immediate revocation of security capabilities in certificateless signature (CLS). In addition, SMC signauture maintains the merits in CLS: implicit certification without key escrow. Unfortunately, most of the existing schemes for CLS and SMC signature are based on bilinear pairing. There are schemes without bilinear pairing such as [1] and [2] which is based on discrete logarithm problem. In this paper, based on the schemes in [2] and [3], we propose another SMC signature scheme without bilinear pairing. Our scheme is existential unforgeable in the random oracle model based on the intractability of the factoring problem. In addition, it is also efficient in signing and verifying.