Paper 2015/125

Multilinear Pseudorandom Functions

Aloni Cohen and Justin Holmgren

Abstract

We define the new notion of a multilinear pseudorandom function (PRF), and give a construction with a proof of security assuming the hardness of the decisional Diffie-Hellman problem. A direct application of our construction yields (non-multilinear) PRFs with aggregate security from the same assumption, resolving an open question of Cohen, Goldwasser, and Vaikuntanathan. Additionally, multilinear PRFs give a new way of viewing existing algebraic PRF constructions: our main theorem implies they too satisfy aggregate security.