Quantum Cryptography Needs a Reboot

Quantum technologies—including quantum computing, ultra-sensitive quantum detectors, and quantum random number generators—are at the vanguard of many engineering fields today. Yet one of the earliest quantum applications, which dates back to the 1980s, still appears very far indeed from any kind of widespread, commercial rollout.

Despite decades of research, there’s no viable roadmap for how to scale quantum cryptography to secure real-world data and communications for the masses.

That’s not to say that quantum cryptography lacks commercial applications. Quantum crypto, which uses delicate quantum states of individual photons to transmit information that cannot be accessed without detection, is a niche industry today. A handful of companies now operate or pay for access to networks secured using quantum cryptography in the United States, China, Austria, and Japan.

According to a recent industry report, six startups plus Toshiba are leading efforts to provide quantum cryptography to governments, large companies (including banks and financial institutions), and small to medium enterprises. But these early customers may never provide enough demand for these services to scale.

“There are very high security players… but there are so few of them,” says Prem Kumar, professor of physics and electrical and computer engineering at Northwestern University. “The vast majority of people… don’t really want to pay anything [for their cryptography]. So it’s one of those Catch-22s. You can’t bring the cost down by heavy-duty engineering, when the user set is so small.”

From a practical standpoint, then, it doesn’t appear that quantum cryptography will be anything more than a physically elaborate and costly—and, for many applications, largely ignorable—method of securely delivering cryptographic keys anytime soon.

This is in part because traditional cryptography, relying as it does on existing computer networks and hardware, costs very little to implement. Whereas quantum crypto requires an entirely new infrastructure of delicate single-photon detectors and sources, and dedicated fiber optic lines. So its high price tag must be offset by a proven security benefit it could somehow deliver—a benefit that has remained theoretical at best.

This is not how the story was expected to play out. [READ MORE]