Our work consists of two constructions. Our first FE construction is provably secure against any attacker that is limited to making all of its private key queries after it sees the challenge ciphertext. (This notion implies selective security.) Our construction makes use of an we introduce called puncturable deterministic encryption (PDE) which may be of independent. With this primitive in place we show a simpleconstruction FE construction.
We then provide a second construction that achieves adaptive security from indistinguishability obfuscation. Our central idea is to achieve an adaptively secure functional encryption by bootstrapping from a one-bounded FE scheme that is adaptively secure. By using bootstrapping we can use "selective-ish'' techniques at the outer level obfuscation level and push down the challenge of dealing with adaptive security is then FE scheme, where it has been already been solved. We combine our bootstrapping framework with a new "key signaling'' technique to achieve our construction and proof.Category / Keywords: public-key cryptography / Functional Encryption, Obfuscation Date: received 29 Jul 2014, last revised 9 Jan 2015 Contact author: bwaters at cs utexas edu Available format(s): PDF | BibTeX Citation Version: 20150109:221130 (All versions of this report) Short URL: ia.cr/2014/588 Discussion forum: Show discussion | Start new discussion