There’s a vast network that keeps our internet running, and it lives under the ocean
The following originally appeared in Forbes
The entire global economy runs on the backbone of a network of fiber-optic cables, but the growing challenge for infrastructure and telecommunications operators is making sure the data that flows through them in form of light doesn’t leak out or get stolen.
One of the most cutting-edge methods for keeping data on fiber-optic cables ultra-secure is a field known as quantum communications. BT Group, the storied British telecommunications giant with more than 30 million retail customers and mobile subscribers, has been researching the method since well before 2015.
“Although this is quantum physics and seems like a hard science topic for a corporation to get involved with, we can see the potential impact all the way down the line,” says Jonathan Legh-Smith, who heads up partnerships and strategic research at BT Group.
The company’s research focus has been on a technique known as quantum key distribution, which refers to using quantum physics to share keys in encrypted communications.
Though the technique probably won’t be put into practice for several years yet, it’s an important area of security research. The advent of powerful quantum-computing techniques could not only supercharge artificial intelligence but crack any code or password. Encryption, some argue, will become completely worthless.
“Take an optical fiber, the thickness of your hair,” says Legh-Smith. “If you bend it, light will start to leak out. If light is coming out, you can detect it, you can tap into it.” Tapping into a fiber-optic cable to steal around 1% of the light passing through is “usually not detectable,” he added.
Legh-Smith couldn’t cite examples of deliberate hacks of fiber-optic cables in this way (“I’m not authorized to know,” he added), but stealing data from underwater cables has plenty of historical precedent.
The secret tapping of undersea cables is said to have helped end the Cold War. In October 1971, U.S. submarines installed devices that wrapped around a copper communications cable used by the Soviet Union and picked up the vibrations of information passing through them. The devices were part of a program known as Operation Ivy Bells.
More recently, whistleblower Edward Snowden revealed that the NSA had also sought to gather some of the data flowing through fiber-optic cables, in a program known as Muscular.
The big worry for telecommunications providers like BT is the scenario of an unknown actor stealing data from a fiber-optic cable and then putting it back in undetected. But harnessing quantum physics can help detect even minor infractions in the data flow, says Legh-Smith.
By setting the polarization, or spin, of the light photons flowing through its network, the act of taking those photons out and "looking at them" already changes their properties, which makes any alteration detectable.
The broader, quantum-based approach to monitoring such hacks is known as a “post-quantum encryption,” and should be deployable across BT’s fiber-optic network in the next five years, Legh-Smith predicts. “It may be longer," he adds. "There are challenges.”
One of the challenges is funding, though for now the British government has been stepping up. It announced that £315 million ($405 million) of public funds would go into the development of quantum technologies over the next five years. In the U.S., politicians are reportedly racing to solidify a 10-year, $1.2 billion initiative to support quantum science too.
BT conducted field trials for quantum key distribution back in 2015 together with Toshiba, in which it was able to use the laws of quantum physics to decrypt data over a fiber-optic line in real time. Legh-Smith describes it as a world first. But the challenge now is to get the technology small and cost-effective enough to work across the company’s network. “It needs to be a solution we can integrate into our services,” he says.
Some of BT’s higher-end customers are financial firms and those healthcare companies that send and receive highly sensitive data, and these would be some of the early users of a quantum-based system that could detect hacks on a fiber-optic line, he added.
Legh-Smith was speaking from the sidelines of the Quantum Computing Showcase in London, where universities, startups and tech companies displayed a variety of applications for the next wave of technology that promises to use quantum mechanics to harness the behaviour of photons.
You can read Forbes’ two-minute guide to quantum computing here. Otherwise, here’s an even shorter primer on the technology behind it: At the quantum level, data is designated by qubits instead of bits. While classical bits can only be in a binary state (a 0 or a 1), the potential range for qubits is much greater. They can be thought of as being at any point on a sphere, and can thus contribute to carrying significantly more information, for less power.
The approach means that quantum computing not only stands to boost AI and encrypted communications. Quantum sensing and measurement could also let machines detect light signatures from around corners, or “see” objects underground by measuring pressure or magnetic fields.
BT is working closely with the universities of Cambridge, York and Bristol on its quantum communications research. “We’ve got this innovation phase to go through,” Legh-Smith says. “It’s a real endeavor.”