Our construction achieves maximum versatility by allowing multiple authorities to control the key distribution for an exponential number of attributes. In addition, the ciphertext policies of our system are sufficiently expressive and overcome the restriction that ``each attribute is used only once'' that constrained previous constructions. Besides versatility, another goal of our work is to increase efficiency and practicality. As a result, we use the significantly faster prime order bilinear groups rather than composite order groups. The construction is non-adaptively secure in the random oracle model under a non-interactive q-type assumption, similar to one used in prior works. Our work extends existing ``program-and-cancel'' techniques to prove security and introduces two new techniques of independent interest for other ABE constructions. We provide an implementation and some benchmarks of our construction in Charm, a programming framework developed for rapid prototyping of cryptographic primitives.
Category / Keywords: public-key cryptography / attribute-based, multi-authority, large-universe Original Publication (with major differences): Financial Crypto 2015 Date: received 10 Jan 2015 Contact author: yannis rouselakis at gmail com Available format(s): PDF | BibTeX Citation Version: 20150112:072131 (All versions of this report) Short URL: ia.cr/2015/016 Discussion forum: Show discussion | Start new discussion