• Colt is at the forefront of quantum-safe networking developments
• The network operator has completed a ‘world-first’ transatlantic trial with Nokia and Adtran
• It plans to launch commercial quantum-safe networking services this year

Colt, one of the pioneers in the development of quantum-safe networking services, has completed what it describes as a “world-first transatlantic trial” using technology from Adtran and Nokia. 

The international network operator says it successfully transmitted 100 gigabit Ethernet traffic from its network in London, UK, to its landing station at Bellport, New York, across its terrestrial and transatlantic subsea infrastructure, including its capacity on Google’s Grace Hopper subsea cable that runs from the south-west of the UK to New York state. The transmission was secured using quantum‑safe encryption enabled by Adtran’s ML-KEM Post-Quantum Cryptography (PQC) and Nokia’s advanced Pre-Shared Key (PSK) technology. 

According to Colt, the trial “marks a breakthrough in strengthening security on the busiest subsea corridor for global internet traffic, which supports AI workloads, streaming and enterprise cloud services between Europe and the US”. 

Later this year, the operator plans to launch quantum-safe networking services “including solutions based on pre-shared key (PSK), post-quantum cryptography (PQC), quantum key distribution (QKD), and hybrid models across terrestrial and subsea networks,” noted Colt.  

The company’s chief operating officer, Buddy Bayer, stated: “Protecting data in transit from quantum threats is one of the most critical challenges businesses will face. This trial demonstrates Colt’s commitment to delivering secure, future-ready connectivity that powers the global economy and keeps our customers one step ahead in the quantum era.”

The transmission is the latest in a series of quantum-safe networking trials undertaken by Colt and various partners. In June 2025, Colt teamed up with Nokia and Honeywell’s Aerospace Technologies division to “explore quantum-safe networking using satellite communications,” while in April last year it announced the successful completion of a quantum-secured encryption trial across a number of optical connections on its European network in partnership with Adtran, Ciena, ID Quantique (IDQ), Nokia and Toshiba (see this Adtran announcement for additional details).    

Colt is recognised as one of the leading developers of quantum-safe networking services, according to our most recent market perception survey of the telecom sector, while Nokia ranked second, and Adtran 14th, in the vendors regarded by the industry as leaders in the development of technology that will enable quantum-safe networking. You can find out more in our free-to-download DSP Leaders report, the 14-page Quantum-Safe Networking Market Perception Report. 

You can keep up to speed with the latest developments in our dedicated telecom-related quantum technology channel. 

- Ray Le Maistre, Editorial Director, TelecomTV