An Identity Based Proxy Signature Scheme Secure in the Standard Model

Identity-based proxy signature scheme is a special identity-based public key cryptography. In 2005, Gu and Zhu showed how to construct an identity-based proxy signature scheme from any secure identity-based signature scheme, but this construction need PKG to extract the secret proxy signing keys. David Galindo, Javier Herranz and Eike Kiltz proposed another generic construction of identity-based proxy signature scheme in Asiacrypt 2006. This construction method leads to schemes that are somewhat inefficient. This paper present the first direct construction of an identity based proxy signature scheme. Our scheme is based on an identity based signature scheme proposed by Paterson and Schuldt in 2006. The scheme´s security is proven in the standard model and rests on the hardness of the computational Diffie-Hellman problem in groups equipped with a pairing.