Blockchain-Based Federated Learning Enhanced by Post-Quantum Cryptography and Homomorphic Encryption for Improved Security

Federated Learning (FL) has emerged as a promising decentralized machine learning approach, enabling multiple clients to collaboratively train models without sharing raw data, thus preserving privacy. However, traditional FL architectures face significant security and privacy challenges, including single points of failure, susceptibility to poisoning attacks, incentive misalignment, and vulnerabilities to quantum computing threats. Integrating blockchain technology into FL frameworks has shown potential in addressing some of these issues by providing decentralized trust, transparency, and resilience. Nonetheless, the advent of quantum computing poses imminent threats to classical cryptographic schemes employed within blockchain systems. To future-proof blockchain-based federated learning (BC-FL), it is essential to incorporate post-quantum cryptography (PQC) and advanced privacy-preserving techniques such as homomorphic encryption (HE), which can further protect data privacy by allowing computations on encrypted data without decryption.

This research proposal aims to develop a comprehensive blockchain-based federated learning (BC-FL) framework incorporating PQC and HE to achieve robust security against quantum threats and enhanced privacy preservation. The primary objectives of this research are:

1. To analyze existing security vulnerabilities in current blockchain-based federated learning systems.

2. To design a secure BC-FL architecture integrating post-quantum cryptographic algorithms for robust key management and secure communication.

3. To implement homomorphic encryption schemes enabling secure computation on encrypted data within the FL model aggregation process.

4. To evaluate the performance, scalability, and security of the proposed framework through extensive simulations and practical experiments.

5. To propose guidelines for transitioning existing FL implementations towards quantum-resistant cryptographic standards.