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[2602.22269] CQSA: Byzantine-robust Clustered Quantum Secure Aggregation in Federated Learning
Summary
The paper presents Clustered Quantum Secure Aggregation (CQSA), a novel framework for Byzantine-robust secure aggregation in federated learning, addressing vulnerabilities in current quantum secure aggregation protocols.
Why It Matters
As federated learning becomes increasingly prevalent, ensuring the security and integrity of model updates is crucial. CQSA offers a solution to the challenges posed by Byzantine attacks, enhancing the robustness of quantum-assisted federated learning systems, which is vital for applications requiring high data privacy and security.
Key Takeaways
- CQSA partitions clients into clusters for localized quantum aggregation, improving fidelity and robustness.
- The framework addresses the limitations of existing quantum secure aggregation protocols, particularly in large-scale scenarios.
- Statistical analysis methods are employed to identify malicious contributions from Byzantine clients.
Computer Science > Machine Learning arXiv:2602.22269 (cs) [Submitted on 25 Feb 2026] Title:CQSA: Byzantine-robust Clustered Quantum Secure Aggregation in Federated Learning Authors:Arnab Nath, Harsh Kasyap View a PDF of the paper titled CQSA: Byzantine-robust Clustered Quantum Secure Aggregation in Federated Learning, by Arnab Nath and 1 other authors View PDF HTML (experimental) Abstract:Federated Learning (FL) enables collaborative model training without sharing raw data. However, shared local model updates remain vulnerable to inference and poisoning attacks. Secure aggregation schemes have been proposed to mitigate these attacks. In this work, we aim to understand how these techniques are implemented in quantum-assisted FL. Quantum Secure Aggregation (QSA) has been proposed, offering information-theoretic privacy by encoding client updates into the global phase of multipartite entangled states. Existing QSA protocols, however, rely on a single global Greenberger-Horne-Zeilinger (GHZ) state shared among all participating clients. This design poses fundamental challenges: fidelity of large-scale GHZ states deteriorates rapidly with the increasing number of clients; and (ii) the global aggregation prevents the detection of Byzantine clients. We propose Clustered Quantum Secure Aggregation (CQSA), a modular aggregation framework that reconciles the physical constraints of near-term quantum hardware along with the need for Byzantine-robustness in FL. CQSA randomly partition...
