Security News > 2022 > December > US passes the Quantum Computing Cybersecurity Preparedness Act – and why not?
Remember quantum computing, and the quantum computers that make it possible?
Quantum computing enthusiasts claim the performance improvements will be so dramatic that encryption keys that could once comfortably have held out against even the richest and most antagonistic governments in the world for decades.
We're not much better off than Schrödinger's famous cat, which is happily, if apparently impossibly, both dead AND alive until someone decides to check up on it, whereupon it immediately ends up alive XOR dead. But quantum computing enthusiasts claim that, with sufficiently careful construction, a quantum device could reliably extract the right answer from the superposition of all answers, perhaps even for calculations chunky enough to chew through cryptographic cracking puzzles that are currently considered computationally infeasible.
Grover's algorithm given a big and powerful enough quantum computer, claims to be able to complete the same feat with about the square root of the usual effort, thus doing lookups that would normally take 22N tries in just 2N tries instead. Shor's quantum factorisation algorithm.
That's why the US National Institute of Standards and Technology, back in 2016, started a long-running public competition for unpatented, open-source, free-for-all-uses cryptographic algorithms that are considered "post-quantum", meaning that they can't usefully be accelerated by the sort of quantum computing tricks described above.
The rapid progress of quantum computing suggests the potential for adversaries of the United States to steal sensitive encrypted data today using classical computers, and wait until sufficiently powerful quantum systems are available to decrypt it.