The fear is that a quantum computer would allow an adversary like China to quickly decode U.S. military messages or consumer banking transactions.
“Without effective mitigation, the impact of adversarial use of a quantum computer could be devastating to [national security systems] and our nation,” the Pentagon said in 2021.
Microsoft has acknowledged the national security factor, and has even framed quantum security as a race against China.
“While most believe that the United States still holds the lead position, we cannot afford to rule out the possibility of a strategic surprise or that China may already be at parity with the United States,” Microsoft President Brad Smith wrote in a blog post in April.
The government has led an effort to move encryption to so-called post-quantum methods, which can’t be broken by a quantum computer. Companies such as Apple have already started to integrate post-quantum encryption into its services like iMessage.
But past communications can still contain secrets. Intelligence agencies and other hackers often collect encrypted data in the expectation that one day it can be decrypted.
For now, much of the work in quantum is still fairly academic.
Most of the advanced hardware companies today are working on “error correction,” or a variety of methods meant to reduce the number of errors, and make them less harmful when they happen.
In present-day quantum computers, the qubits fail as often as 1 out of 1,000 times they are used, according to Microsoft researchers. Microsoft said last week that it was able to reduce the error rate by 1,000-fold thanks to a new approach.
Several improvements in error correction have been announced over the past year, which is one reason why researchers and engineers are increasingly confident that they’ll be able to build a quantum computer.
The next issue to address is scaling up the computers.
Google’s new Willow chip has 105 qubits. Microsoft’s Majorana chip has eight. IBM’s Starling plans to have 200 qubits. Amazon’s Ocelot chip has 14 qubits. In the coming years, these numbers have to go way up. Google and Microsoft say a truly useful quantum computer will need 1 million qubits.
WATCH: Quantum computing is reaching an inflection point