IACR News item: 28 November 2012
Jiang Zhang \\and Zhenfeng Zhang \\and Yu Chen
ePrint ReportTo meet such a practical requirement, we first introduce proxy re-encryption with non-interactive opening (PRENO), and formally
define the notions of security against \\textit{chosen ciphertext
attacks} (CCA) and \\textit{proof soundness}. Our security model is natural and strong since we allow the CCA adversary to adaptively choose public keys for malicious users (i.e., a chosen key model), and a scheme secure in previous models (i.e., knowledge of secret key models) is not necessarily secure in our model. Then, we present an efficient PRENO scheme which satisfies our security notions based on the decisional bilinear Diffie-Hellman (DBDH) assumption in the standard model. Compared with two previous PRE schemes, our scheme is competitive in several aspects. First, its CCA security is proved in a strong security model under a well-studied assumption in the standard model. Second, it has a good overall performance in terms of ciphertext length and computational cost. Third, it first provides non-interactive opening for PRE schemes.
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