Cambridge, United Kingdom, March 02, 2026 -- Toshiba Europe Limited today announced a new capability that enables the interconnection of geographically separated quantum key distribution (QKD) networks without the need for additional hardware. This capability allows network operators to offer their customers global quantum‑resistant connectivity, enhancing protection of sensitive data against retrospective decryption by future quantum computers.

“Q‑day” — the point at which quantum computers are able to break the cryptography protecting today’s online communications — is widely anticipated to occur within the coming years. Even before Q‑day arrives, malicious actors are already carrying out so‑called “harvest now, decrypt later” attacks, in which sensitive data is collected and stored with the intention of decrypting it once large‑scale quantum computers become available. Information with long‑term sensitivity, including financial records, medical data, corporate intellectual property, and government secrets, is therefore already at risk, creating an urgent need for a transition to quantum‑safe networking.

Today’s network security relies largely on public‑key cryptography, which is based on mathematical problems that are difficult — but not impossible — to solve. A sufficiently powerful quantum computer, however, will be able to solve all commonly used public‑key algorithms efficiently. This vulnerability has driven strong interest in quantum‑based security protocols that have been proven secure from first principles and are immune to all computational attacks, including those using quantum computers.

Fibre‑based QKD technology is now sufficiently mature to support networks spanning an entire country or even a continent. However, until now it has not been possible to create the intercontinental links required to build a truly global quantum‑safe network.

In parallel with ongoing satellite-based QKD developments, which extend the global interconnection of terrestrial QKD networks by establishing QKD links between ground stations and orbiting satellites, Toshiba is introducing a new capability that uses quantum‑resistant algorithms, known as post-quantum cryptography (PQC), to bridge geographically separated QKD networks, as illustrated in the figure below. This approach addresses the immediate and urgent need for global connectivity today, and fully integrates into Toshiba’s existing quantum‑safe networking solution with current hardware. It is available from today.

“While QKD can already support national‑scale networks, many customers are seeking quantum‑safe connections to offices located on the other side of the world,” said Dr Andrew Shields, Vice President of Toshiba Europe and Head of its Quantum Technology Division. “By integrating post‑quantum algorithmic key exchange into our Key Distribution System platform, we can deliver quantum‑safe connectivity across networks spanning multiple continents. Within the next few years, we will further enhance our platform by integrating satellite‑based QKD, expanding the options available for global quantum‑safe communications.”

The deployment of a hybrid architecture that combines both QKD and PQC algorithms enables network operators to distribute quantum‑resistant keys across a global network. These keys can then be used to deliver quantum‑safe encrypted data services worldwide.

Toshiba’s PQC bridging solution delivers clear business benefits for network operators, including:

• The ability to offer a wide range of quantum‑resistant encrypted services and applications worldwide, protecting customers from the risks posed by quantum computers
• Rapid and cost‑effective deployment using Toshiba’s quantum‑safe networking solution, with end-to-end key exchange managed through an integrated Key Delivery System
• Reduced business and operational risk, enabled by a flexible, future‑proofed architecture that supports cost‑effective upgrades, including the future integration of satellite QKD