CCA-secure unidirectional proxy re-encryption in the adaptive corruption model without random oracles

Jian Weng, MinRong Chen, YanJiang Yang, Robert Deng, KeFei Chen, Feng Bao
2010 Science China Information Sciences  
Proxy re-encryption (PRE), introduced by Blaze, Bleumer and Strauss in Eurocrypt'98, allows a semitrusted proxy to convert a ciphertext originally intended for Alice into an encryption of the same message intended for Bob. PRE has recently drawn great interest, and many interesting PRE schemes have been proposed. However, up to now, it is still an important question to come up with a chosen-ciphertext secure unidirectional PRE in the adaptive corruption model. To address this problem, we
more » ... a new unidirectional PRE scheme, and prove its chosen-ciphertext security in the adaptive corruption model without random oracles. Compared with the best known unidirectional PRE scheme proposed by Libert and Vergnaud in PKC'08, our schemes enjoys the advantages of both higher efficiency and stronger security. 1 In refs. [2, 3, 5] , for a single-hop unidirectional PRE scheme, the original ciphertext is named second level ciphertext, and the transformed ciphertext is called first level ciphertext. Through out this paper, we also follow these terminologies. 2 Libert, B, Vergnaud, D. Unidirectional chosen-ciphertext secure proxy re-encryption. http://hal.inria.fr/inria-00339530/en/. This is the extended version of [5]. 3 Zhang, X, Chen, M.R, Li, X. Comments on Shao-Cao's proxy re-encryption scheme from PKC 2009. Cryptology ePrint Archive, Report 2009/344 (2009), http://eprint.iacr.org. )
doi:10.1007/s11432-010-0047-3 fatcat:knvhng6yu5b3pfsagp23hknkma