Two extensions of the ring signature scheme of Rivest–Shamir–Taumann

Two extensions of RST (Rivest, Shamir and Taumann) ring signature are proposed which keep the form of RST ring signature unchanged. One extension is to implement the verifiability property with which the real signer is able to prove that she actually signed the ring signature if she publishes her secret value. In contrast to the available verifiable ring signatures, this scheme is very simple, secure and efficient. In this scheme only the glue value of RST ring signature is replaced by the output of a hash function which takes as input a secret value and some signature parameters and the real signer is able to prove himself any times. The other extension is to construct an anonymous subliminal channel in RST ring signature so that the subliminal sender (the real signer) is able to keep herself subliminal anonymous to the subliminal receiver. The subliminal anonymity is implemented for the first time in this paper. In addition, if the sender wants to revoke the subliminal anonymity, she is able to use the first extension.