Quantum computers—exotic machines that can solve practical problems that would stymie any conventional supercomputer—remain years or decades away. However, yesterday President Joe Biden’s administration took a step to anticipate the eventual deployment of such machines. In a new national security memorandum, the White House instructs federal agencies to prepare to shift from the encryption algorithms used today to secure communications on the internet and other networks to new algorithms resistant to attack by a quantum computer.

The memo envisions the shift beginning in 2024, when the first standard for such “post-quantum cryptography” should emerge, and being complete before 2035. Fortunately for internet companies, such postquantum cryptography will involve changes mostly in software. “You don’t need a quantum computer to implement these postquantum solutions,” says Dustin Moody, a mathematician with the National Institute of Standards and Technology (NIST). Still, he says, “The transition should be quite challenging, as with any crypto transition that we’ve done.”

Whereas a conventional computer processes information by flipping bits that can be set to 0 or 1, a quantum computer manipulates quantum bits or qubits that can be set to 0, 1, or, thanks to the weird rules of quantum mechanics, 0 and 1 at the same time. Such two-ways-at-once states enable a quantum computer to encode all possible solutions to certain problems as abstract quantum waves. Set things up right and, in the guts of the machine, the waves will interfere so that the incorrect solutions cancel one another, and the right solution pops out.