Identity-based proxy signatures: a generic construction and a concrete scheme from RSA

摘要

Proxy signatures allow an entity to delegate its signing capability to a proxy which can sign messages on behalf of the delegator. We examine identity-based versions of proxy signatures which employ identity strings in place of randomly generated public keys. First, we give a new generic construction of identity-based proxy signatures from identity-based standard signatures and show that our generic construction is secure if the underlying identity-based standard signature is secure. In addition, we present the first identity-based proxy signature from Rivest, Shamir and Adleman (RSA), secure under the one-wayness of RSA in the random oracle model. We should highlight that the proxy key exposure attack cannot be applied to our proposed constructions. Copyright (C) 2015 John Wiley & Sons, Ltd.