Improved Dual System ABE in Prime-Order Groups via Predicate Encodings

We present a modular framework for the design of efficient adaptively secure attribute-based encryption(ABE) schemes for a large class of predicates under the standard k-Lin assumption in prime-order groups; this is thefirst uniform treatment of dual system ABE across different predicates and across both composite and prime-ordergroups. Via this framework, we obtain concrete efficiency improvements for several ABE schemes. Our frameworkhas three novel components over prior works: (i) new techniques for simulating composite-order groups in prime-order ones, (ii) a refinement of prior encodings framework for dual system ABE in composite-order groups, (iii) anextension to weakly attribute-hiding predicate encryption (which includes anonymous identity-based encryptionas a special case).