US passes the Quantum Computing Cybersecurity Preparedness Act – and why not? – Naked Security
Remember quantum computing, and the quantum computers that make it possible?
Along with superstrings, dark matter, gravitons and controlled fusion (hot or cold), quantum computing is a concept that many people have heard of, even if they know little more about any of these topics than their names.
Some us are vaguely better informed, or think we are, because we have an idea why they’re important, can recite short but inconclusive paragraphs about their basic underlying concepts, and broadly assume that they’ll either be proved, discovered or invented in due course.
Of course, practice sometimes lags far behind theory – controlled nuclear fusion, such as you might use for generating clean(ish) electrical energy, is no more than 20 years away, as the old joke goes, and has been since the 1930s.
And so it is with quantum computing, which promises to confront cryptographers with new and faster techniques for parallel password cracking.
Indeed, 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…
…might suddenly turn out to be breakable in half an afternoon by a modest group of spirited enthusiasts at your local makerspace.
Superpositions of all answers at once
Quantum computers pretty much claim to allow certain collections of calculations – algorithms that would usually need to be computed over and over again with ever-varying inputs until a correct output turned up – to be performed in a single iteration that simultaneously “evaluates” all possible outputs internally, in parallel.
This supposedly creates what’s known as a superposition, in which the correct answer appears right away, along with lots of wrong ones.
Of course, that’s not terribly exciting on its own, given that we already know at least one of the possible answers will be correct, but not which one.
In fact, 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.
Computationally infeasible is a jargon term that loosely means, “You will get there in the end, but neither you, nor perhaps the earth, nor even – who …….