Cryptology ePrint Archive: Report 2008/304

A New Randomness Extraction Paradigm for Hybrid Encryption

Eike Kiltz and Krzysztof Pietrzak and Martijn Stam and Moti Yung

Abstract: We present a new approach to the design of IND-CCA2 secure hybrid encryption schemes in the standard model. Our approach provides an efficient generic transformation from 1-universal to 2-universal hash proof systems. The transformation involves a randomness extractor based on a 4-wise independent hash function as the key derivation function. Our methodology can be instantiated with efficient schemes based on standard intractability assumptions such as DDH, QR and Paillier. Interestingly, our framework also allows to prove IND-CCA2 security of a hybrid version of 1991's Damgaard's ElGamal public-key encryption scheme under the DDH assumption.

Category / Keywords: public-key cryptography / Chosen-ciphertext security, hybrid encryption, hash proof systems, ElGamal

Publication Info: This is the full version of the paper in EUROCRYPT 2009

Date: received 7 Jul 2008, last revised 22 Jul 2009

Contact author: kiltz at cwi nl

Available format(s): PDF | BibTeX Citation

Version: 20090722:101546 (All versions of this report)

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