Toshiba Europe Limited and Quantum Bridge Technologies Demonstrate Global Quantum-Safe Networking capability
Toshiba Europe Limited (Toshiba) and Quantum Bridge Technologies Inc. (QBT) today announced the successful demonstration of an international communication network delivering provably secure, quantum-safe data transmission. The system integrates Toshiba’s Quantum Key Distribution (QKD) technology with QBT’s Distributed Symmetric Key Establishment (DSKE) platform and was deployed on field-installed fibre infrastructure in collaboration with Telehouse Canada Inc. (Telehouse), a subsidiary of KDDI Corporation.
The milestone demonstration, unveiled at the Optical Fiber Communication Conference (OFC) 2026, shows how existing metropolitan QKD networks can be interconnected across continents using DSKE. By leveraging carrier-grade infrastructure and emerging interoperability standards, the project represents an important step toward practical, global-scale communication that remains secure even in the era of quantum computing.
Advancing Information-Theoretic Security
The network is based on information-theoretic security (ITS), also known as provable security. This model ensures that confidential data remains protected regardless of the computational power available to an attacker, offering resilience not only against current threats but also against future advances in supercomputing and large-scale quantum computing.
QKD is already widely deployed to deliver provable security, with numerous fibre-based metropolitan QKD networks operating worldwide. However, extending this level of protection across continents has remained challenging due to the absence of ultra-long-distance fibre QKD systems and the limited availability of satellite-based QKD services.
Bridging Continents Securely
One common approach to linking geographically separated QKD networks is the use of post-quantum cryptography (PQC)—algorithms designed to resist attacks from quantum computers. While PQC standards have recently matured and are gaining adoption, they rely on computational security assumptions that could change as new technologies emerge.
QBT’s DSKE technology offers an alternative approach to long-distance connectivity. The protocol uses symmetric cryptography, secret sharing, and pre-shared entropy to establish keys without relying on public-key infrastructure. Because it is inherently resistant to quantum attacks, DSKE enables long-haul links that maintain the same level of provable security as QKD networks.
By combining high-speed QKD metro networks with DSKE-enabled long-distance connections, Toshiba and QBT demonstrated how quantum-safe communication can be extended globally.
Live Network Demonstration
The demonstration connected an operational QKD network in Cambridge with a newly established QKD network in Toronto. The systems were hosted within Telehouse data centres and connected through installed fibre infrastructure, demonstrating seamless operation within carrier-grade environments.
A key feature of the deployment was the use of emerging interoperability standards from the European Telecommunications Standards Institute (ETSI) Industry Specification Group on QKD. The network adopted the latest draft of the ETSI GS QKD 020 Interoperable Key Management Specification, enabling standardized communication between key-management software in QKD systems and DSKE platforms. This approach highlights the potential for multi-vendor interoperability in future quantum-safe networking environments.
Reflecting on the achievement, Andrew Shields, Vice President of Toshiba and Head of its Quantum Technology Division, said:
“This demonstration shows how quantum key distribution networks can be extended beyond metropolitan distances while preserving the same level of provable security. By combining high-speed QKD networks with DSKE technology and emerging interoperability standards, we are taking an important step toward practical global communication infrastructure that remains secure in the quantum computing era.”
Together, Toshiba’s QKD technology and QBT’s DSKE solution deliver provably secure key exchange across both metropolitan and global distances—creating a scalable, future-proof foundation for protecting the world’s most sensitive communications.
Further technical details are available in the full OFC technical paper: https://www.toshiba.eu/quantum/wp-content/uploads/resources/QKD_DSKE-Submit.pdf.
For more information about Toshiba’s quantum technology solutions and QKD services, visit:
https://www.toshiba.eu/quantum/
