Communication-efficient and Differentially-private Distributed Nash Equilibrium Seeking with Linear Convergence
Xiaomeng Chen, Wei Huo, Kemi Ding, Subhrakanti Dey, Ling Shi
TL;DR
This work addresses distributed Nash equilibrium seeking under simultaneous privacy and communication constraints on directed graphs. It proposes CDP-NES, a unified framework that fuses difference compression with Laplacian noise and constant-step updates to achieve linear convergence to a neighborhood of the NE while guaranteeing $\epsilon$-differential privacy. Theoretical results show a linear convergence rate $\mathcal{O}(\rho(\mathbf{A})^k)$ with $\rho(\mathbf{A})<1$ and a mean-square NE error scaling as $\bar{\theta}^2$, with $\bar{\theta}$ tied to privacy budgets; privacy is ensured by a Laplace mechanism with $\theta_i > 2\gamma\eta K M/\epsilon_i$ under a bounded-gradient assumption. Simulations on a connectivity-control game demonstrate substantial communication savings from compression and competitive convergence under privacy constraints, highlighting practical impact for large-scale distributed decision-making with privacy guarantees.
Abstract
The distributed computation of a Nash equilibrium (NE) for non-cooperative games is gaining increased attention recently. Due to the nature of distributed systems, privacy and communication efficiency are two critical concerns. Traditional approaches often address these critical concerns in isolation. This work introduces a unified framework, named CDP-NES, designed to improve communication efficiency in the privacy-preserving NE seeking algorithm for distributed non-cooperative games over directed graphs. Leveraging both general compression operators and the noise adding mechanism, CDP-NES perturbs local states with Laplacian noise and applies difference compression prior to their exchange among neighbors. We prove that CDP-NES not only achieves linear convergence to a neighborhood of the NE in games with restricted monotone mappings but also guarantees $ε$-differential privacy, addressing privacy and communication efficiency simultaneously. Finally, simulations are provided to illustrate the effectiveness of the proposed method.
