Security Arguments for Partial Delegation with Warrant Proxy Signature Schemes

Proxy signature is an important cryptographic primitive and has been suggested in numerous applications. In this paper, we present an attack on the aggregate-signaturebased proxy signature schemes, then point out there are two flaws in BPW notion of security for proxy signature. Furthermore, we give arguments for partial delegation with warrant proxy signature schemes. We construct a new proxy signature scheme and prove that it is secure against existentially forgery on adaptively chosen-message attacks and adaptively chosen-warrant attacks under the random oracle model.