Cryptology ePrint Archive: Report 2008/509

Chosen-Ciphertext Secure Proxy Re-Encryption without Pairings

Jian Weng and Robert H. Deng and Shengli Liu and Kefei Chen and Junzuo Lai and Xuan Wang

Abstract: Proxy re-encryption (PRE), introduced by Blaze, Bleumer and Strauss, allows a semi-trusted proxy to convert a ciphertext originally intended for Alice into an encryption of the same message intended for Bob. Proxy re-encryption has found many practical applications, such as encrypted email forwarding, secure distributed file systems, and outsourced filtering of encrypted spam. In ACM CCS'07, Canetti and Hohenberger presented a bidirectional PRE scheme with chosen-ciphertext security, and left an important open problem to construct a chosen-ciphertext secure proxy re-encryption scheme without pairings. In this paper, we propose a bidirectional PRE scheme with chosen-ciphertext security. The proposed scheme is fairly efficient due to two distinguished features: (i) it does not use the costly bilinear pairings; (ii) the computational cost and the ciphertext length decrease with re-encryption.

Category / Keywords: Proxy re-encryption, bilinear pairing, chosen-ciphertext security.

Publication Info: This is a full and improved version which appears in CANS 2008, M.K. Franklin, L.C.K. Hui, and D.S. Wong (Eds.), volume 5339 of LNCS, Springer-Verlag, 2008.

Date: received 1 Dec 2008, last revised 4 May 2009

Contact author: cryptjweng at gmail com

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Version: 20090504:065348 (All versions of this report)

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