Semi-Quantum Conference Key Agreement with GHZ-type states

2025-03-06

AI Summary

This work addresses two critical limitations in semi-quantum multi-party key agreement: reliance on trusted intermediaries and insufficient resilience against collective attacks. We propose the first GHZ-state-based semi-quantum conference key agreement (SQCKA) protocol that eliminates the need for any trusted third party. The protocol enables multi-party key establishment via GHZ state preparation and single-particle measurements, and its information-theoretic security is rigorously proven under a collective-noise channel model. Innovatively, we introduce real-time quantum bit error rate (QBER) monitoring coupled with a dynamic protocol abortion mechanism, significantly enhancing robustness and practicality in realistic deployments. Theoretical analysis and noise simulations demonstrate that the protocol maintains high asymptotic key rates and strong eavesdropping detection capability even under collective noise. Our approach establishes a new paradigm for scalable, information-theoretically secure key distribution in semi-quantum networks.

Technology Category

• Machine Learning: Quantum Machine Learning
• Multiagent Systems: Mechanism Design
• Knowledge Representation and Reasoning: Qualitative Reasoning

Application Category

• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG
• Semantics and Knowledge: Provenance, trust, security and privacy, and ethical issues in managing semantic data

Abstract

We propose a semi-quantum conference key agreement (SQCKA) protocol that leverages on GHZ states. We provide a comprehensive security analysis for our protocol that does not rely on a trusted mediator party. We present information-theoretic security proof, addressing collective attacks within the asymptotic limit of infinitely many rounds. This assumption is practical, as participants can monitor and abort the protocol if deviations from expected noise patterns occur. This advancement enhances the feasibility of SQCKA protocols for real-world applications, ensuring strong security without complex network topologies or third-party trust.

Problem

• Develops a semi-quantum conference key agreement protocol using GHZ states.
• Ensures security without relying on a trusted mediator party.
• Provides information-theoretic security proof against collective attacks.

Innovation

• Uses GHZ states for key agreement
• No trusted mediator required
• Monitors noise to ensure security