Public Verifiable Signcryption Schemes with Forward Secrecy Based on Hyperelliptic Curve Cryptosystem

Abstract

Signcryption is a process of combining encryption and signature into a single logical step. Traditional signcryption schemes provide message confidentiality and sender authentication, sender authentication can only be provided after unsigncryption of signcrypted text, so the third part can only verify the sender after breaching the confidentiality. In public verifiable signcryption schemes a third party or judge can verify authenticity of sender without breaching the confidentiality and without knowing the receiver private key, the judge just needs the signcrypted text and some additional parameters. In this paper, we proposed a resource efficient Hyperelliptic curve cryptosystem based signcryption schemes to provide message confidentiality, authentication, integrity, unforgeability, non-repudiation, along with forward secrecy and public verifiability. In case of dispute the judge can verify signcrypted text directly without sender/receiver private parameters. Our schemes are resource efficient and can be applied to any resource constrained environments.