Marking the Pace: A Blockchain-Enhanced Privacy-Traceable Strategy for Federated Recommender Systems

TL;DR

This paper introduces LIBERATE, a blockchain and differential privacy-enhanced federated recommender system that ensures data privacy and traceability during data sharing and model updates in IoT environments.

Contribution

The paper proposes a novel blockchain-based traceability mechanism combined with local differential privacy for federated recommenders, addressing privacy and data flow transparency issues.

Findings

Blockchain-based traceability effectively ensures data flow transparency.

LIBERATE maintains recommendation accuracy while protecting privacy.

System evaluations confirm efficiency and privacy preservation in real-world scenarios.

Abstract

Federated recommender systems have been crucially enhanced through data sharing and continuous model updates, attributed to the pervasive connectivity and distributed computing capabilities of Internet of Things (IoT) devices. Given the sensitivity of IoT data, transparent data processing in data sharing and model updates is paramount. However, existing methods fall short in tracing the flow of shared data and the evolution of model updates. Consequently, data sharing is vulnerable to exploitation by malicious entities, raising significant data privacy concerns, while excluding data sharing will result in sub-optimal recommendations. To mitigate these concerns, we present LIBERATE, a privacy-traceable federated recommender system. We design a blockchain-based traceability mechanism, ensuring data privacy during data sharing and model updates. We further enhance privacy protection by incorporating local differential privacy in user-server communication. Extensive evaluations with the real-world dataset corroborate LIBERATE's capabilities in ensuring data privacy during data sharing and model update while maintaining efficiency and performance. Results underscore blockchain-based traceability mechanism as a promising solution for privacy-preserving in federated recommender systems.