An Improved Multi-Receiver Generalized Signcryption Scheme
Caixue Zhou · International journal of network security · 2015
Generalized signcryption (GSC) scheme can adaptively work as an encryption scheme, a signature scheme or a signcryption scheme with only one algorithm and one keypair. It can realize using the same keypair in more different cryptographic primitives. It is very suitable for storage-constrained environments, like the embedded systems, smart cards and wireless sensor networks. In this paper, we analyze a multi-receiver GSC scheme, and show that it cannot achieve indistinguishability-adaptive chosen ciphertext attack (IND-CCA2) secure in the pure encryption mode and hybrid encryption mode. We further propose a revised version of the scheme, which resolves the security issues of the original scheme without sacrificing its high efficiency and simple design. Our improved scheme can be proved to be IND-CCA2 secure and existentially unforgeable-adaptive chosen message attack (EUF-CMA) under computational Diffie-Hellman (CDH) assumption.