At PKC 2006, Yang, Wong, Deng and Wang proposed the notion of anonymous signature schemes where signatures do not reveal the signer's identity, as long as some parts of the message are unknown. They also show how to modify the RSA scheme and the Schnorr scheme to derive anonymous signatures in the random oracle model. Here we present a general and yet very efficient approach to build such anonymous schemes from ordinary signature schemes. When instantiated in the random oracle model, our

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... n is essentially as efficient as the original scheme, whereas our construction also supports an almost as efficient instantiation in the standard model.