Constructing Designated-Verifier Ring Signature and Ring Signcryption under the k-CCA2 Assumption

Ring signatures are one of the signatures that can enhance the anonymity of the users who want to sign documents not only in the way of authentication but also privacy. In this paper, we propose a simple but secure designated verifier ring signature scheme from bilinear pairing. The security of the scheme is proved under the k-CAA2 assumption. Furthermore, a ring signcryption scheme is also presented from the new designated verifier ring signature scheme.