Colt Technology Services has completed what it describes as the world’s first transatlantic trial of quantum-safe encrypted data transmission, marking a notable milestone in efforts to protect global internet traffic from future quantum computing threats.
The trial successfully transmitted data at 100GbE across Colt’s terrestrial and transatlantic subsea networks, using quantum-resilient encryption technologies supplied by Nokia and Adtran.
The test focused on safeguarding data in motion against the potential decryption capabilities of quantum computers, which are expected to eventually undermine many of today’s widely used cryptographic standards. For enterprises operating across continents, particularly those dependent on cloud computing, artificial intelligence workloads, and real-time data exchange, the ability to secure traffic across subsea routes is increasingly viewed as a strategic requirement rather than a long-term research objective.
According to Colt Technology Services, the trial covered one of the busiest subsea corridors for global internet traffic between Europe and the United States. A central component of the test was the Grace Hopper subsea cable, which adds 352 terabits per second of capacity to the route and is considered critical infrastructure for transatlantic connectivity. By applying quantum-safe encryption at full operational speeds, Colt aimed to demonstrate that enhanced security can be delivered without compromising performance.
The trial forms part of a broader program of quantum-security pilots conducted by Colt in partnership with technology vendors. Earlier tests included a quantum-safe optical wave network trial in April 2025, also involving Nokia and Adtran. Colt has also signalled plans to explore space-based quantum cryptography, positioning the transatlantic subsea trial as one element of a wider push toward end-to-end quantum-resilient networks spanning land, sea, and potentially space.
Colt Chief Operating Officer Buddy Bayer said protecting data in transit from quantum threats represents one of the most pressing security challenges facing global businesses. He noted that the trial demonstrates Colt’s intention to provide future-ready connectivity designed to keep customers ahead of emerging risks as quantum computing capabilities advance.
Commercializing Quantum-Resilient Services
From a technical perspective, the trial combined Nokia’s advanced Pre-Shared Key technology with Adtran’s ML-KEM-based Post-Quantum Cryptography solutions. Together, these approaches are designed to ensure that encryption keys and data remain secure even if intercepted and stored for future decryption by quantum-enabled adversaries. Colt confirmed that secure transmission was achieved across both terrestrial and subsea infrastructure at 100GbE, aligning with the performance requirements of large enterprises and service providers.
Looking ahead, Colt plans to commercialize quantum-resilient services later in 2026. The planned portfolio includes solutions based on Pre-Shared Keys, Post-Quantum Cryptography, Quantum Key Distribution, and hybrid models that combine classical and quantum-safe techniques. These services are intended for sectors with heightened security and compliance needs, including financial services, healthcare, government, defence, and technology partners developing quantum-safe applications.
For B2B customers, the trial underscores a shift in the telecoms industry from experimental quantum security concepts toward deployable, standards-aligned solutions. As enterprises increasingly plan for a post-quantum security environment, demonstrations at transatlantic scale suggest that quantum-safe networking is moving closer to operational reality.
Executive Insights FAQ
Why is quantum-safe encryption important for subsea networks?
Subsea cables carry vast volumes of sensitive global data, making them a priority target for future quantum-enabled threats.
What makes this trial a world first?
It demonstrated quantum-safe encrypted data transmission at 100GbE across a live transatlantic subsea route.
Which technologies were used in the trial?
The test combined Pre-Shared Key technology and Post-Quantum Cryptography from Nokia and Adtran.
When will quantum-resilient services be commercially available?
Colt plans to launch quantum-resilient network services later in 2026.
Which industries are expected to benefit most?
Financial services, healthcare, government, defence, and technology developers with high data security requirements.
