Cryptology ePrint Archive: Report 2012/638

Cryptanalysis and Improvement of a Multi-Receiver Generalized Signcryption Scheme

Cai-xue Zhou

Abstract: Generalized signcryption (GSC) scheme can adaptively work as an encryption scheme, a signature scheme or a signcryption scheme with only one algorithm. It is very suitable for storage-constrained environments. 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.

Category / Keywords: public-key cryptography / public-key cryptography

Publication Info: no publication

Date: received 8 Nov 2012

Contact author: charlesjjjx at 126 com

Available formats: PDF | BibTeX Citation

Version: 20121111:162045 (All versions of this report)

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