While they wrestle with the immediate danger posed by hackers today, US government officials are preparing for another, longer-term threat: attackers who are collecting sensitive, encrypted data now in the hope that they’ll be able to unlock it at some point in the future.
The threat comes from quantum computers, which work very differently from the classical computers we use today. Instead of the traditional bits made of 1s and 0s, they use quantum bits that can represent different values at the same time. The complexity of quantum computers could make them much faster at certain tasks, allowing them to solve problems that remain practically impossible for modern machines—including breaking many of the encryption algorithms currently used to protect sensitive data such as personal, trade, and state secrets.
While quantum computers are still in their infancy, incredibly expensive and fraught with problems, officials say efforts to protect the country from this long-term danger need to begin right now.
“The threat of a nation-state adversary getting a large quantum computer and being able to access your information is real,” says Dustin Moody, a mathematician at the National Institute of Standards and Technology (NIST). “The threat is that they copy down your encrypted data and hold on to it until they have a quantum computer.”
Faced with this “harvest now and decrypt later” strategy, officials are trying to develop and deploy new encryption algorithms to protect secrets against an emerging class of powerful machines. That includes the Department of Homeland Security, which says it is leading a long and difficult transition to what is known as post-quantum cryptography.
“We don’t want to end up in a situation where we wake up one morning and there’s been a technological breakthrough, and then we have to do the work of three or four years within a few months—with all the additional risks associated with that,” says Tim Maurer, who advises the secretary of homeland security on cybersecurity and emerging technology.
DHS recently released a road map for the transition, beginning with a call to catalogue the most sensitive data, both inside the government and in the business world. Maurer says this is a vital first step “to see which sectors are already doing that, and which need assistance or awareness to make sure they take action now.”
Preparing in advance
Experts say it could still be a decade or more before quantum computers are able to accomplish anything useful, but with money pouring into the field in both China and the US, the race is on to make it happen—and to design better protections against quantum attacks.
The US, through NIST, has been holding a contest since 2016 that aims to produce the first quantum-computer-proof algorithms by 2024, according to Moody, who leads NIST’s project on post-quantum cryptography.
Transitioning to new cryptography is a notoriously tricky and lengthy task, and one it’s easy to ignore until it’s too late. It can be difficult to get for-profit organizations to spend on an abstract future threat years before that threat becomes reality.
“If organizations aren’t thinking about the transition now,” says Maurer, “and then they become overwhelmed by the time the NIST process has been completed and the sense of urgency is there, it increases the risk of accidental incidents … Rushing any such transition is never a good idea.”
As more organizations begin to consider the looming threat, a small and energetic industry has sprouted up, with companies already selling products that promise post-quantum cryptography. But DHS officials have explicitly warned against purchasing them, because there is still no consensus about how such systems will need to work.
“No,” the department stated unequivocally in a document released last month. “Organizations should wait until strong, standardized commercial solutions are available that implement the upcoming NIST recommendations to ensure interoperability as well as solutions that are strongly vetted and globally acceptable.”
But experts are pessimistic about how the transition will go.
If it takes a long time for quantum computers to get to the point where they can solve a useful problem, “I think companies will forget the hype and implement the weakest thing that comes out of NIST until they are suddenly reminded of the problem in 30 years,” Vadim Lyubashevsky, a cryptographer at IBM who’s working on post-quantum cryptographic algorithms with NIST, told MIT Technology Review last year.
And that is exactly the scenario national security officials want to avoid.