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

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. ∗ Supported by National Defense Science and Engineering Graduate Fellowship. † Supported by NSF CNS-0716199, CNS-0915361 and Air Force Office of Scientific Research (AFO SR) under the MURI award for “Collaborative policies and assured information...

• Type: Conference
• Year: 2010
• Where: TCC
• Authors: Allison B. Lewko, Brent Waters
• Keywords: Composite Order Groups, Cryptography, Secure Hibe Scheme, TCC 2010, Technique Includes Tags