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.