Paper 2008/323

A new identity based proxy signature scheme

Bin Wang

Abstract

Proxy signature schemes allow a proxy signer to generate proxy signatures on behalf of an original signer. Mambo et al. first introduced the notion of proxy signature and a lot of research work can be found on this topic nowadays. Recently, many identity based proxy signature schemes were proposed. However, some schemes are vulnerable to proxy key exposure attack. In this paper, we propose a security model for identity based proxy signature schemes. Then an efficient scheme from pairings is presented. The presented scheme is provably secure in the random oracle model. In particular, the new scheme is secure against proxy key exposure attack.