Computationally private information retrieval with polylogarithmic communication

Abstract

We present a single-database computationally private information retrieval scheme with polylogarithmic communication complexity. Our construction is based on a new, but reasonable intractability assumption, which we call the ɸ-Hiding Assumption (ɸHA): essentially the dificulty of deciding whether a small prime divides ɸ(m), where m is a composite integer of unknown factorization.