ISSN : 1796-203X
Volume : 4    Issue : 6    Date : June 2009

Provably Secure Certificate-based Proxy Signature Schemes
Jiguo Li, Lizhong Xu, and Yichen Zhang
Page(s): 444-452
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In this paper, we first propose the definition and security model of certificate-based proxy signature
(CBPS). We then show that the certificate-based proxy signature scheme presented by Kang, Park
and Hahn in CT-RSA 2004 are insecure against key replacement attacks. We further propose two
certificate-based proxy signature schemes, which are shown to be existentially unforgeable against
adaptive chosen message attacks under the computational Diffie-Hellman assumption in the
random oracle model. Compared with the certificate-based proxy signature scheme in CT-RSA
2004, one of our schemes enjoys the same signature length and computation cost, another one
requires a little more computation and communication cost.

Index Terms
certificate-based signature; proxy signature; key replacement attack