Certificateless Ring Signature Scheme from Anonymous Subsets

In a ring signature scheme from anonymous subsets,a member of a setcan freely choose a family of subsets including their own subset tocompute a signature which enjoys two properties: (1) the external verifier is convinced that all members of some subset in the subsetshave cooperated to compute the signature; (2) he has no informationabout which subset has actually signed the message. Certificateless public key cryptography was first introduced by Al-Riyami andPaterson in Asiacrypt 2003. In certificateless cryptography, it does not require the use of certificates to guarantee the authenticity of users´ public keys. Meanwhile, certificateless cryptography has not the key escrow problem which exists in the identity-based cryptography. In this paper, we propose a certificateless ring signature scheme (CL-Ring) from anonymous subsets.This scheme is provably secure in the random oracle model.