As China Leads Quantum Computing Race, U.S. Spies Plan for a World with Fewer Secrets

Back in 1994, when quantum computers existed only as so much chalk on a blackboard, mathematician Peter Shor invented what may soon prove to be their killer app.Shor trained his efforts on a calculation called "factoring," which ordinarily nobody but a mathematician would care about, except it just happens to be an Achilles heel of the internet. If someone were to invent a computer that could perform this operation quickly, messages that are currently hidden from hackers, terrorists, military adversaries, governments and competitors would be as easy to read as a Stephen King novel.Shor, of course, didn't have such a computer. He was writing an algorithm, or program, for a hypothetical machine that might one day exploit the weird properties of atoms and subatomic particles, as described by the theory of quantum mechanics, to perform calculations...