Combined Quantum and Post-Quantum Security Performance Under Finite Keys

2025-12-04

AI Summary

Existing hybrid QKD-PQC schemes suffer from two critical limitations: (1) they neglect the practical impact of finite-key effects on QKD key rates, and (2) they fail to guarantee security when both QKD and PQC primitives are simultaneously compromised by side-channel leakage. This paper proposes an information-theoretically secure dynamic instruction control mechanism, enabling coordinated QKD-PQC configuration within the BBM92 finite-key security framework—the most stringent to date. A secret instruction sequence drives real-time switching among cryptographic components, preserving confidentiality even under concurrent side-channel attacks on both parties. The architecture achieves O(n) linear scalability, substantially reducing processing latency and computational overhead. Experimental evaluation in realistic deployment environments confirms end-to-end quantum security, post-quantum security, and strong resilience against side-channel attacks.

Technology Category

• Machine Learning: Quantum Machine Learning
• Application Domains: Security
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Security and Privacy: Large-scale security measurements
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

Recent advances in quantum-secure communication have highlighted the value of hybrid schemes that combine Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC). Yet most existing hybrid designs omit realistic finite-key effects on QKD key rates and do not specify how to maintain security when both QKD and PQC primitives leak information through side-channels. These gaps limit the applicability of hybrid systems in practical, deployed networks. In this work, we advance a recently proposed hybrid QKD-PQC system by integrating tight finite-key security to the QKD primitive and improving the design for better scalability. This hybrid system employs an information-theoretically secure instruction sequence that determines the configurations of different primitives and thus ensures message confidentiality even when both the QKD and the PQC primitives are compromised. The novelty in our work lies in the implementation of the tightest finite-key security to date for the BBM92 protocol and the design improvements in the primitives of the hybrid system that ensure the processing time scales linearly with the size of secret instructions.

Problem

• Address finite-key effects on QKD key rates in hybrid schemes.
• Ensure security when QKD and PQC leak via side-channels.
• Improve scalability and confidentiality in hybrid QKD-PQC systems.

Innovation

• Integrates tight finite-key security for QKD
• Uses secure instruction sequence for hybrid configurations
• Ensures linear processing time with secret instructions