Attacking Shortest Paths by Cutting Edges

TL;DR

This paper introduces the Force Path Cut problem, demonstrating its APX-hardness, and presents efficient approximation algorithms for manipulating shortest paths in networks, with practical applications in network security and routing.

Contribution

The paper formulates the Force Path Cut problem, proves its APX-hardness, and develops the PATHATTACK algorithm along with heuristics for targeted edge and node removal.

Findings

PATHATTACK guarantees a logarithmic approximation factor.

Algorithms perform well on real and synthetic networks.

Targeted edge and node cuts effectively alter shortest paths.

Abstract

Identifying shortest paths between nodes in a network is a common graph analysis problem that is important for many applications involving routing of resources. An adversary that can manipulate the graph structure could alter traffic patterns to gain some benefit (e.g., make more money by directing traffic to a toll road). This paper presents the Force Path Cut problem, in which an adversary removes edges from a graph to make a particular path the shortest between its terminal nodes. We prove that this problem is APX-hard, but introduce PATHATTACK, a polynomial-time approximation algorithm that guarantees a solution within a logarithmic factor of the optimal value. In addition, we introduce the Force Edge Cut and Force Node Cut problems, in which the adversary targets a particular edge or node, respectively, rather than an entire path. We derive a nonconvex optimization formulation for these problems, and derive a heuristic algorithm that uses PATHATTACK as a subroutine. We demonstrate all of these algorithms on a diverse set of real and synthetic networks, illustrating the network types that benefit most from the proposed algorithms.