International Association for Cryptologic Research (IACR)
Abstract
Proxy signature is an important cryptographic primitive and has
been suggested in numerous applications. In this paper, we present
an attack on the aggregate-signature-based 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