Constraint-Based Privacy Preserving-Path Computation Element

Abstract

Information privacy and protection is fundamental in the context of path computation. When a path computation client (PCC) requests the shortest path between two nodes from a path computation element (PCE), it desires to do so while protecting the sensitive information carried by the query as well as the overall topology of the network. The authors provide a novel framework to compute the shortest path, between a source and a destination, subject to a constraint, represented in the case by a required minimum bandwidth, while preserving the privacy of both client and server. By employing a secure homomorphic encryption scheme, the PCE can blindly compute the path while being oblivious to the content of the encrypted queries. The output of the PCE computation is an encrypted path that is only decipherable by its original secret key. The implementation using the homomorphic scheme over the integers from Van Dijk, Gentry, Halevi, and Vaikuntanathan (DGHV) shows promising results that the authors analyze in detail throughout this paper.