Where Quantum Key Distribution Is Deployed in 2026
Quantum key distribution has moved out of the lab, and networks carry traffic on it today, from China’s national backbone at one end to short commercial trials and research testbeds at the other. This range is important, as deployment can mean a lot of different things. An operational carrier network and a 45-day pilot aren’t the same thing, and this roundup tries to keep them straight.
One pattern does hold across the map: most large, long-distance QKD networks depend on trusted relay nodes, because ordinary fiber can’t regenerate a quantum signal the way it boosts a classical one. And in the UK and the US especially, the companies building QKD are working in countries whose own cyber agencies tell them to prefer post-quantum cryptography for the most sensitive systems. None of these deployments makes a blockchain signature quantum-resistant, though QKD can protect some of the communications and custody infrastructure around it.
Where quantum key distribution is deployed today
China runs the largest QKD network on the planet, and it isn’t close. The national system, called CN-QCN, stretches past 10,000 km of fiber through 145 backbone nodes, and it interconnects with the older Beijing–Shanghai backbone to push the combined mileage above 12,000 km.
Of those 145 nodes, 104 are trusted relays that pass keys hop by hop, and 41 are access points. Six ground stations link the fiber to the Jinan-1 quantum microsatellite, which extends reach between distant cities. It grew out of the 4,600 km satellite-ground network China reported in 2021, which used the earlier Micius satellite.
The system serves users in government and finance, with energy operators in the mix, though public reporting doesn’t name most of them. If you want proof that QKD can run at national scale, this is it. It also shows the cost of doing so. Those 104 relay sites are 104 boxes someone has to be trusted to run objectively.
Europe is building EuroQCI
Europe’s push is coordinated under EuroQCI. All 27 EU member states have signed on, with national and cross-border projects at very different stages of build-out. Deutsche Telekom and AIT recently won an EU mandate to help build the quantum backbone.
The space segment centers on a prototype QKD satellite, EAGLE-1, whose launch has slipped repeatedly and now probably won’t happen before late 2027 or early 2028. A laser ground station for EAGLE-1 is part of that architecture. The EU’s stated aim has been a functional system around 2027, but with the satellite delayed and EAGLE-1 itself framed as a validation mission, that timeline no longer looks realistic. EuroQCI is real and funded, and it’s still mostly under construction.
Switzerland: the long-running example
Switzerland has the longest track record. ID Quantique used a QKD system to secure Geneva’s election-result transmission in 2007, one of the earliest real-world quantum-cryptography installations anywhere, and the vendor said in 2017 that it was still protecting federal and cantonal votes.
On the finance side, ID Quantique and Mt Pelerin built a QKD-backed proof of concept in 2020 for a digital-asset custody system aimed at institutions. Geneva separately launched a 262 km quantum-network research platform in 2025. These protect the plumbing around private keys, the storage and the links. They don’t touch the on-chain signatures themselves.
The UK opened QKD to commercial trials
BT and Toshiba run a quantum-secured metro network across London, with customers including the consultancy EY and the bank HSBC connecting over it in commercial trials. Access has been extended through Equinix data centers too. It’s a service used by customers, but BT still prefers calling it a trial.
The contrast sits inside one country. The UK’s National Cyber Security Centre said in 2025 it won’t support QKD for government or military use, and considers post-quantum cryptography the better mitigation. UK industry markets and trials QKD; the national cyber authority advises against it for the highest-assurance systems.
Asia beyond China
South Korea is working on the hardware. SK Telecom is developing photonic-integrated QKD meant to shrink bulky optics onto chips and, eventually, make them cheap to manufacture at semiconductor scale. Korean telecom and banking companies have also demonstrated QKD and post-quantum cryptography protecting communications between bank sites, a hybrid setup that stops short of a live production banking system.
Japan got there early. The Tokyo QKD Network has run since 2010 as a trusted-node testbed, an early example of the architecture later used in bigger networks.
The United States hangs back
The US is the outlier. It has real activity: EPB in Chattanooga runs the country’s first commercially accessible quantum-network testbed, where companies and researchers can install and test quantum equipment on metro fiber. JPMorgan has done two things worth separating. One was a 2022 lab proof of concept in which QKD protected the data stream carrying its Liink blockchain application. The other was a 2024 project linking two of its data centers over deployed fiber with QKD-secured VPN tunnels.
But federal policy leans the other way. The NSA doesn’t support QKD for national-security systems, nor does it expect to approve it until there’s a solution for known limitations, and points to its cost and its reliance on trusted relays among them. It favors post-quantum cryptography as cheaper and easier to maintain. So, US QKD stays in testbeds and finance pilots, with nothing close to China’s national build-out.
What today’s QKD deployments tell us
Put the deployments side by side and the shape is clear. QKD runs as high-value point-to-point links, built by governments and telecoms with a few banks alongside, and the long-distance ones lean on trusted nodes, though shorter direct links and some newer architectures don’t have to. It’s real and spreading. It’s also narrow. The loudest official skepticism comes from exactly two places: in the UK and the US, companies keep building QKD even as their national cyber authorities steer the highest-assurance systems toward post-quantum cryptography.
If you’re a crypto holder, the finance examples are the ones you should pay attention to. JPMorgan’s QKD protected the network traffic around a blockchain application, and Switzerland’s custody work protects key-storage and communication infrastructure, but neither makes an on-chain signature resistant to quantum forgery. That needs a quantum-resistant signature scheme, and QKD doesn’t provide one. The tool for that job is post-quantum cryptography. QKD is genuinely on the map now. It’s just not the thing standing between a quantum computer and your coins.