Paper 2008/254

An Efficient Identity-based Ring Signcryption Scheme

Zhenchao ZHU and Yuqing ZHANG and Fengjiao WANG

Abstract

ID-based ring signcryption schemes (IDRSC) are usually derived from bilinear parings, a powerful but computationally expensive primitive. The number of paring computations of all existing ID-based ring signcryption schemes from bilinear pairings grows linearly with the group size, which makes the efficiency of ID-based schemes over traditional schemes questionable. In this paper, we present a new identity-based ring signcryption scheme, which only takes four pairing operations for any group size and the scheme is proven to be indistinguishable against adaptive chosen ciphertext ring attacks (IND-IDRSC-CCA2) and secure against an existential forgery for adaptive chosen messages attacks (EF-IDRSC-ACMA).