Google is beginning an experiment in Chrome to test a new post-quantum cryptographic algorithm designed to secure encrypted communications for many decades to come.
The test is Google’s attempt to see how resistant the algorithm is to attacks by quantum computers, a next-generation kind of machine that uses quantum bits and the principles of quantum physics to solve difficult problems. Researchers have been working on quantum computers for years, and there are some in operation today, but they’re relatively small. The machines hold promise for research, but they also present serious challenges for cryptographers.
“While they will, no doubt, be of huge benefit in some areas of study, some of the problems that they are effective at solving are the ones that we use to secure digital communications. Specifically, if large quantum computers can be built then they may be able to break the asymmetric cryptographic primitives that are currently used in TLS, the security protocol behind HTTPS,” Matt Braithwaite, a software engineer at Google, said in a post announcing the experiment.
“The post-quantum algorithm might turn out to be breakable even with today’s computers.”
The cryptographic primitives used in today’s protocols rely on the difficulty of factoring enormous numbers. Mathematicians and cryptographers have speculated that quantum computers will be able to solve those problems far faster than traditional machines, calling into question the long-term security of the protocols we use now. As Braithwaite points out, any encrypted traffic recorded now may be decrypted in the future with quantum computing. So Google decided to test a new post-quantum algorithm known as New Hope in Chrome.
“Today we’re announcing an experiment in Chrome where a small fraction of connections between desktop Chrome and Google’s servers will use a post-quantum key-exchange algorithm in addition to the elliptic-curve key-exchange algorithm that would typically be used. By adding a post-quantum algorithm on top of the existing one, we are able to experiment without affecting user security,” Braithwaite said.
“The post-quantum algorithm might turn out to be breakable even with today’s computers, in which case the elliptic-curve algorithm will still provide the best security that today’s technology can offer. Alternatively, if the post-quantum algorithm turns out to be secure then it’ll protect the connection even against a future, quantum computer.”
Google is hoping to see how New Hope performs in real-world conditions and see whether it holds promise for the future. The company is not alone in working on this problem. The NSA has begun planning for a post-quantum future, as well, and Microsoft, IBM, and other companies are actively working to build large quantum computers.
Right now, the New Hope algorithm is in the Chrome Canary build, an early test version of the browser.