Reliable Federated Learning for Mobile Networks

TLDR

Federated learning leverages distributed mobile device data for privacy‑preserving model training, but unreliable or malicious updates can compromise task integrity. The study aims to identify trustworthy workers by introducing a reputation metric and proposing a reliable worker selection scheme. The approach uses a central aggregator to collect local updates and a consortium blockchain to manage worker reputation and select reliable participants. Numerical analysis shows the scheme improves reliability of federated learning in mobile networks.

Abstract

Federated learning, as a promising machine learning approach, has emerged to leverage a distributed personalized dataset from a number of nodes, for example, mobile devices, to improve performance while simultaneously providing privacy preservation for mobile users. In federated learning, training data is widely distributed and maintained on the mobile devices as workers. A central aggregator updates a global model by collecting local updates from mobile devices using their local training data to train the global model in each iteration. However, unreliable data may be uploaded by the mobile devices (i.e., workers), leading to frauds in tasks of federated learning. The workers may perform unreliable updates intentionally, for example, the data poisoning attack, or unintentionally, for example, low-quality data caused by energy constraints or high-speed mobility. Therefore, finding out trusted and reliable workers in federated learning tasks becomes critical. In this article, the concept of reputation is introduced as a metric. Based on this metric, a reliable worker selection scheme is proposed for federated learning tasks. Consortium blockchain is leveraged as a decentralized approach for achieving efficient reputation management of the workers without repudiation and tampering. By numerical analysis, the proposed approach is demonstrated to improve the reliability of federated learning tasks in mobile networks.