QNS Services Successfully Completes PoC for Quantum-Safe Communication Combining Toshiba's QKD System and Quantum Bridge's DSKE

QNS Services Co., Ltd. (hereafter, QNS Services), as a solution provider for quantum-resistant cryptography, has succeeded in a Proof of Concept (PoC) for a redundant quantum-safe communication system that achieves both information-theoretic security and high availability, in collaboration with Toshiba Corporation (hereafter, Toshiba).

This demonstration established a two-site configuration simulating inter-hub connections in a corporate network. The primary line utilized Toshiba's QKD (Quantum Key Distribution) system, while the secondary line employed the DSKE (Distributed Symmetric Key Establishment) key exchange method operating on Quantum Bridge's SDS (Symmetric-Key Distribution System). SDS is a symmetric-key exchange platform equipped with crypto-agility, capable of implementing PQC and DSKE, and cooperating with QKD.

The PoC applied these to an IPsec VPN environment built with an enterprise router (SAE) and verified key management linkage via the SKIP API, assuming disaster recovery for line disconnections. As a result, it was confirmed that even if a failure occurs on the primary line, the system automatically switches to the secondary line, allowing ongoing IPsec VPN communication sessions to continue. This demonstrated that communication without interruption is possible while maintaining information-theoretic security in a redundant configuration that combines different quantum-resistant key distribution methods and different routes.

With the advancement of quantum computing technology, higher levels of security and availability are required for corporations and social infrastructure. Through this PoC, QNS Services has confirmed the effectiveness of integration technologies for incorporating quantum-safe communication technology into networks close to actual operation.

In this PoC, Toshiba provided technical cooperation regarding the QKD system, while network-wide design and evaluation/provision of other methods were conducted based on each company's roles.

Key Points of This Demonstration Test

1. **Demonstration of Switching for Redundant Key Exchange Method Configuration** Combined QKD on the main line and DSKE on the secondary line, demonstrating continuous encrypted communication during switching and reverting.

2. **Confirmation of Resilience through Different Methods and Routes** By combining QKD using dedicated lines with DSKE that can utilize internet connections, it was demonstrated that secure communication can continue even during dedicated line failures.

**Tadaharu Takeda, Manager of the QKD Business Promotion Office, ICT Solutions Division at Toshiba, commented:**

"We recognize this PoC by QNS Services as demonstrating the effectiveness of enhancing the availability of inter-hub communications in corporate networks, even during disasters. We believe there is significance in verifying a redundant configuration combining key distribution technologies with information-theoretic security in a near-real-world environment. Toshiba is advancing the development of related technologies and working towards social implementation with its partners."

Future Outlook

Based on the knowledge gained from this demonstration, QNS Services aims to launch a redundant quantum-safe communication solution by 2026, targeting sectors demanding high security and business continuity, such as finance, public services, and healthcare. Moving forward, we will support the implementation of communication infrastructure that maintains information-theoretic security not only for domestic hub connections but also for diverse network environments, including remote islands and overseas bases.

Company Overviews

* **QNS Services Co., Ltd.** : A solution provider in the field of quantum-resistant cryptography. As the general agent in Japan for Quantum Bridge Technologies, Inc., they provide support for the implementation of quantum-resistant security solutions, system integration, and related services. They also offer sales and implementation services for products developed by group companies.

* **Toshiba Corporation** : Toshiba has been engaged in research and development of Quantum Key Distribution (QKD) since 1999, achieving numerous milestones in key distribution speed and communication distance. In the field of quantum secure communication, alongside advanced technology R&D, Toshiba is advancing practical implementation and deployment with an eye on social implementation through repeated demonstrations and PoCs with partners.