Functional Encryption with Bounded
Collusions via Multi-Party Computation
Sergey Gorbunov
(
Vinod Vaikuntanathan (
Hoeteck Wee (
Abstract:
We construct functional encryption schemes for polynomial-time computable
functions secure against an a-priori bounded
polynomial number of collusions, assuming the existence of semantically
secure public-key encryption schemes. During the course of our constructions,
we show a “bootstrapping theorem” that constructs a $q$-query
functional encryption scheme for arbitrary functions starting from a
$q$-query functional encryption scheme for bounded-degree functions. All our constructions rely heavily on
techniques from secure multi-party computation and randomized encodings.
Our constructions are secure under a strong simulation-based definition of
functional encryption.