Chosen-Ciphertext Secure Proxy Re-encryption without Pairings

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 reencryption 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.

• Type: Conference
• Year: 2008
• Where: CANS
• Authors: Robert H. Deng, Jian Weng, Shengli Liu, Kefei Chen
• Keywords: Bidirectional Pre Scheme, CANS 2008, Cryptology, Proxy Re-encryption, Proxy Reencryption Scheme