Cryptology ePrint Archive: Report 2009/482

New Techniques for Dual System Encryption and Fully Secure HIBE with Short Ciphertexts

Allison Lewko and Brent Waters

Abstract: We construct a fully secure HIBE scheme with short ciphertexts. The previous construction of Boneh, Boyen, and Goh was only proven to be secure in the selective model, under a non-static assumption which depended on the depth of the hierarchy. To obtain full security, we apply the dual system encryption concept recently introduced by Waters. A straightforward application of this technique is insufficient to achieve short ciphertexts, since the original instantiation of the technique includes tags that do not compress. To overcome this challenge, we design a new method for realizing dual system encryption. We provide a system in composite order groups (of three primes) and prove the security of our scheme under three static assumptions.

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Publication Info: this is a full version of a paper that will appear in TCC 2010

Date: received 29 Sep 2009, last revised 29 Aug 2010

Contact author: alewko at cs utexas edu

Available format(s): PDF | BibTeX Citation

Version: 20100830:031939 (All versions of this report)

Short URL: ia.cr/2009/482

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