Data Privacy in Machine Learning: Challenges and Federated Learning Solutions
Abstract
Federated Learning (FL) enables collaborative model training across distributed devices while preserving data locality, making it a promising paradigm for privacy-sensitive applications. This paper presents a structured and comprehensive survey of FL studies with a focus on confidentiality and privacy-preserving mechanisms. This paper first reviews major FL architectures including centralized, decentralized, FedAvg, clustered, asynchronous, and heterogeneous approaches and provides a comparative discussion of their performance, scalability, and implementation complexity. Recent survey literature (2023-2025) is analyzed to highlight evolving challenges related to fairness, heterogeneity, and system-level security. Subsequently, key confidentiality methods are comparatively reviewed, including Differential Privacy (DP), Homomorphic Encryption (HE), Trusted Execution Environments (TEE), Secure Aggregation (SA), and Secure Multi-Party Computation (SMPC). Their relative trade-offs in computation cost, scalability, and protection strength are examined across diverse application domains, such as healthcare, finance, and IoT. The findings indicate that no single mechanism offers complete protection, and effective privacy assurance in FL requires hybrid approaches that balance efficiency with confidentiality. Finally, open research gaps and future directions are identified, emphasizing the need for adaptive, resource-aware, and trust-anchored FL frameworks capable of maintaining privacy guarantees under real-world heterogeneity and dynamic participation.
Keywords
References
- Yin X., Zhu Y., and Hu J. (2021). A comprehensive survey of privacy-preserving federated learning: a taxonomy, review, and future directions, ACM Computing Surveys, 54, (6), 1-36.
- Peng L. and Qiu M. (2024). AI in healthcare data privacy-preserving: enhanced trade-off between security and utility. Proceedings of Knowledge Science, Engineering and Management (KSEM), 349-360.
- Paracha A, Arshad J, Farah M. B., and Ismail K. (2024). Machine learning security and privacy: a review of threats and countermeasures, EURASIP Journal on Information Security, 2024, (1).
- Ma S., Cao Y., and Xiong L. (2021). Transparent contribution evaluation for secure federated learning on blockchain. 37th International Conference on Data Engineering Workshops (ICDEW), IEEE, 88-91.
- Bonawitz K., Eichner H., Grieskamp W., Huba D., Ingerman A., Ivanov V., Kiddon C., Konečný J., Mazzocchi S., McMahan H. B., Van Overveldt T., Petrou D., Ramage D., and Roselander J. (2019). Towards federated learning at scale: system design, arXiv:1910.06664.
- Zhang C., Xie Y., Bai H., Yu B., Li W., and Gao Y. (2021). A survey on federated learning, Knowledge-Based Systems, (216), 106775.
- Truong N., Sun K., Wang S., Guitton F., and Guo Y. (2021). Privacy preservation in federated learning: an insightful survey from the GDPR perspective, Computers & Security, (110), 102402.
- Kairouz P., McMahan H., B., Avent B., Bellet A., Bennis M., and et al. (2021). Advances and open problems in federated learning, arXiv:1912.04977.
Details
Primary Language
English
Subjects
Machine Learning (Other)
Journal Section
Review
Publication Date
May 31, 2026
Submission Date
August 1, 2025
Acceptance Date
November 17, 2025
Published in Issue
Year 2026 Volume: 13 Number: 1