Quantum Key Distribution and the Crypto-Apocalypse

DARPA has been running a quantum network since that same year, and the Secure Communication based on Quantum Cryptography (SECOQC) network, a project of the E.U., has been running since 2008. U.S. research non-profit Battelle has been making solid progress on QKD for years, and has had an encrypted fiber network in place since 2013.

And QKD is gaining steam. In February, SK Telecom and Nokia announced an agreement to conduct joint research that combines SK’s QKD acumen and Nokia’s next-generation optical transport. Toshiba announced in September that it had reached quantum key distribution speed in excess of 10Mbps, seven times faster than the speeds it had achieved only a year before. The quantum race has also been pushing increasingly into space, with China’s quantum satellite, Micius, being joined by Japan’s SOCRATES and others.

It’s those satellite advances that brought about one of the most noteworthy recent QKD headlines. In September, Chinese and Austrian researchers used Micius to facilitate a video conference between scientists 4,600 miles away from one another. The call connected Chunli Bai, president of the Chinese Academy of Sciences in Beijing, with Anton Zeilinger, president of the Austrian Academy of Sciences in Vienna. It built on work from earlier this year that saw researchers within China communicate over distances of 750 miles over channels secured by QKD.

This application is still a far cry from widespread adoption and use of QKD, but it’s part of a series of very encouraging early steps. “Insight must precede application,” University of Vienna Rector Heinz W. Engl said in the wake of the intercontinental call. He was quoting Max Planck, the founding father of quantum physics. “A telephone call illustrates today the innovative potential of fundamental research.”

But QKD isn’t a final answer. It’s only a beginning. Pravahan cites AT&T’s involvement in the INQNET initiative–which he co-founded in collaboration with Caltech and other academic, government, and industry partners– is “looking forward to building quantum networks where communication occurs between multiple nodes in a wide area network while preserving the quantum correlations also called entanglement between the quantum bits (or qubits) that encode the information.” He says that such a network will allow for QKD, but will eventually be capable of much more.

Pravahan notes that there are considerable costs associated with implementing and scaling applications that rely on QKD, but asserts that, given the impending emergence of widespread quantum computing, finding alternative methods of encryption is essential.

“I think, at least in the near future,” Pravahan says, “QKD will play a very important part in network security, especially for highly sensitive communications.”