Multi-input functional encryption and its application in outsourcing computation

Abstract

We study functional encryption and its application in outsourcing computation. Functional encryption is a new primitive first defined by Boneh, Sahai and Waters: given an encryption of a message x and a decryption key skf for a function f, anyone can obtain f(x) but cannot learn anything else about x. In multi-input functional encryption, the secret key skf corresponds to an n-ary function f and takes multiple ciphertexts as its input. Prior works on multi-input functional encryption are based on indistinguishability obfuscation which is either rely on a polynomial set of assumptions or an exponential number of assumptions. In this paper, we construct a multi-input functional encryption scheme without obfuscation. And we show its application in outsourcing computation and construct a multi-client outsourcing computation scheme that is publicly verifiable.