A Strong RSA-based and Certificateless-based Signature Scheme

The certificateless-based signature system allows people to verify the signature without the certificate. For this reason, we do not need the certificate authority (CA) to store and manage users’ certificates and public keys. Certificateless-based signature can also overcome the certificate management problem and the key escrow problem of the traditional signature system. In 2012, Zhang and Mao first designed the certificateless-based signature scheme based on RSA operations; however, their scheme still has latent vulnerabilities. To overcome these shortcomings, we propose an improved version to make the RSA-based certificateless scheme stronger and more secure. Besides, we reduce the computational cost to make our scheme more efficient.