Privacy-Preserved Average Consensus Algorithms with Edge-based Additive Perturbations

TL;DR

This paper introduces a novel privacy-preserving average consensus algorithm that employs edge-based perturbations, ensuring privacy against internal and external threats while maintaining convergence in networked systems.

Contribution

The paper proposes a new two-phase consensus algorithm with edge-based perturbations that guarantees privacy preservation without compromising convergence.

Findings

The algorithm effectively preserves privacy against honest-but-curious agents.

It ensures convergence of the consensus process despite added perturbations.

Privacy is maintained unless all other agents are unable to communicate with the target.

Abstract

In this paper, we consider the privacy preservation problem in both discrete- and continuous-time average consensus algorithms with strongly connected and balanced graphs, against either internal honest-but-curious agents or external eavesdroppers. A novel algorithm is proposed, which adds edge-based perturbation signals to the process of consensus computation. Our algorithm can be divided into two phases: a coordinated scrambling phase, which is for privacy preservation, and a convergence phase. In the scrambling phase, each agent is required to generate some perturbation signals and add them to the edges leading out of it. In the convergence phase, the agents update their states following a normal updating rule. It is shown that an internal honest-but-curious agent can obtain the privacy of a target agent if and only if no other agents can communicate with the target agent.