Cryptology ePrint Archive: Report 2009/194

Analysis and Enhance of Anonymous Signcryption Scheme

Mingwu Zhang and Yusheng Zhong and Pengcheng Li and Bo Yang

Abstract: Ring signcryption, a cryptographic primitive to protect security and privacy, is an encryption and authentication scheme in a single logical step which allows a user to anonymously signcrypt a plaintext on behalf of a group of users that decrypter cannot know who is the actual signcrypter. In 2009, Zhang, Gao, Chen and Geng proposed a novel anonymous signcryption scheme(denoted as the ZGCG scheme) which is more efficient in computational cost and ciphertext length than the related schemes. In this paper, however, we show that the ZGCG scheme has not anonymity secure for the receiver, and then we propose an improved anonymous signcryption scheme that remedies the weakness of the ZGCG scheme. Our proposed scheme satisfies the semantic security, unforgeability, signcrypter identity's ambiguity, and public authenticity. We also give the formal security proof in the random oracle model.

Category / Keywords: secret-key cryptography / digital signatures

Publication Info: Prepared to submit to ProSec09

Date: received 5 May 2009

Contact author: csmwzhang at gmail com

Available format(s): PDF | BibTeX Citation

Note: None

Version: 20090506:020734 (All versions of this report)

Short URL: ia.cr/2009/194

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