A Survey of Digital Signcryption

Signcryption is a cryptographic primitive that fulfills both the functions of digital signature and public key encryption simultaneously, at a cost significantly lower than that required by the traditional signature-then-encryption approach. In this article, the state-of-the-art of signcryption is surveyed. This paper classifies signcryption as PKI-based signcryption, identity-based signcryption and certificateless signcryption according to the authentication method of public keys. Each classification is classified further as basic signcryption, signcryption with special properties and hybrid signcryption. The formal models of PKI-based signcryption and identity-based signcryption are also given. Some possible future work is pointed out. The survey helps in understanding the research work that has been carried out in the area of signcryption from the year 1997 to 2011.