Paper 2015/703 Original: eprint.iacr.org/2015/703 ↗

Point-Function Obfuscation: A Framework and Generic Constructions

Abstract

We give a definitional framework for point-function obfuscation in which security is parameterized by a class of algorithms we call target generators. Existing and new notions are captured and explained as corresponding to different choices of this class. This leads to an elegant question: Is it possible to provide a generic construction, meaning one that takes an arbitrary class of target generators and returns a point-function obfuscator secure for it? We answer this in the affirmative with three generic constructions, the first based on indistinguishability obfuscation, the second on deterministic public-key encryption and the third on universal computational extractors. By exploiting known constructions of the primitives assumed, we obtain new point-function obfuscators, including many under standard assumptions. We end with a broader look that relates different known and possible notions of point function obfuscation to each other and to ours.