Certificateless proxy identity-based signcryption scheme without bilinear pairings

Signcryption, which was introduced by ZHENG, is a cryptographic primitive that fulfils the functions of both digital signature and encryption and guarantees confidentiality, integrity and non-repudiation in a more efficient way. Certificateless signcryption and proxy signcryption in identity-based cryptography were proposed for different applications. Most of these schemes are constructed by bilinear pairings from elliptic curves. However, some schemes were recently presented without pairings. In this paper, we present a certificateless proxy identity-based signcryption scheme without bilinear pairings, which is efficient and secure.