Published: Oct 17, 2025

Security validation of Quantum Key Distribution Networks

Quantum Key Distribution Networks (QKDNs) promise unprecedented security by using the laws of quantum physics to protect data exchange. Yet for many organisations, they remain an experimental technology. The real question is: can QKDNs be integrated reliably and securely into mission-critical environments?

This article examines how NCS validated QKDN performance in real-world conditions, moving beyond theory to proof of enterprise resilience.

Quantum Key Distribution (QKD) is one of the most established technologies in quantum information science. It enables two remote parties to generate and share symmetric encryption keys securely, using the laws of quantum physics rather than mathematical complexity. Because any attempt to intercept the exchange creates detectable disturbances, QKD offers a level of protection that is theoretically immune to even the most powerful future computers.
 

QKDNs hold enormous potential, but enterprises hesitate to adopt without proof of performance. Laboratory tests alone are not enough, business leaders want confidence that QKDNs can withstand high-volume traffic, integrate with existing IT, and perform under real-world stress.
 

To answer these concerns, NCS designed and executed a series of rigorous validation exercises:

• Simulation of enterprise-scale environments to replicate mission-critical workloads
• Stress tests under peak traffic conditions to measure throughput and reliability
• Adversarial simulations to test resilience against potential attacks
• Cross-validation with industry partners to ensure interoperability and credibility

This approach moved validation out of the lab and into environments that resemble real enterprise operations.
 

While there are many perspectives on how to design a Quantum Key Distribution Network (QKDN), far fewer focus on how to evaluate whether these networks are truly effective. QKDNs are designed to protect against quantum-enabled decryption, but without proper validation, the very process of implementation can introduce vulnerabilities that weaken overall network security.

NCS’s validation framework helps organisations bridge this gap. It focuses on answering a simple but critical question: For someone who has deployed a QKDN, how can they be sure it works as intended?

To support that, NCS developed a set of practical test cases that can be applied with limited resources and minimal complexity. These tests assess critical aspects of a QKDN’s performance, resilience, and reliability, ensuring that even early adopters can validate their systems with confidence.

The test cases do not need to be executed sequentially, but the first validating the randomness of the generated keys is foundational. Without true randomness, every layer of quantum security built on top could be compromised.

Together, these validation steps enable organisations to move beyond theoretical assurance and achieve real-world confidence that their QKDN performs securely, consistently, and as designed.
 

Quantum security technologies like QKDN will play a key role in the post-quantum era. But adoption depends on trust. Through rigorous testing and validation, NCS provides enterprises with the assurance that QKDNs can be integrated securely, reliably, and at scale.
 

Go back
Revisit ‘Quantum-safe cryptography: When and how to start’ and ‘Automating discovery of cryptographic assets’ to see the strategic and practical foundations that lead into this validation phase.

Go deeper
Download our comprehensive guide 'Preparing for a quantum-safe future'. This resource brings together all three parts, from migration, to strategy, to automated discovery, to QKDN validation, into one detailed reference.

References

^[1] ETSI. GS QKD 014. Quantum Key Distribution (QKD); Protocol and data format of REST-based key delivery API. February 2019. 

^[2] IMDA. Reference Specification: Quantum Key Distribution Networks. IMDA RS QKDN Issue 1. June 2023. 

^[3] ITU-T. X.1710: Security framework for quantum key distribution networks. October 2020. 

^[4] ITU-T. Y.3804 (2020). Quantum key distribution networks – Control and management. Amendment 1. November 2023. 

^[5] MAS. Advisory on addressing the cybersecurity risks associated with quantum. Circular No. MAS/TCRS/2024/01. 20 February 2024. 

^[6] MAS. MAS Collaborates with Banks and Technology Partners on Quantum Security. Accessed 20 March 2025. 

^[7] Microsoft. CBC decryption vulnerability - .NET | Microsoft Learn. Accessed 21 March 2025. 

^[8] NIST. SP 800-22 Revision 1a. A Statistica Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications. April 2010.