Distributed Calculation of Edge-Disjoint Spanning Trees for Robustifying Distributed Algorithms against Man-in-the-Middle Attacks

Abstract

In this paper we provide a distributed methodology to allow a network of agents, tasked to execute a distributed algorithm, to overcome Man-in-the-middle attacks that aim at steering the result of the algorithm towards inconsistent values or dangerous configurations. We want the agents to be able to restore the correct result of the algorithm in spite of the attacks. To this end, we provide a distributed algorithm to let the set of agents, interconnected by an undirected network topology, construct several $edge-disjoint spanning trees$ by assigning a label to their incident edges. The ultimate objective is to use these spanning trees to run multiple instances of the same distributed algorithm in parallel, in order to be able to detect Man-in-the- middle attacks or other faulty or malicious link behavior (e.g., when the instances yield different results) and to restore the correct result (when the majority of instances is unaffected). The proposed algorithm is lightweight and asynchronous, and is based on iterated depth-first visits on the graph. We complement the paper with a thorough analysis of the performance of the proposed algorithms. IEEE