Shor's algorithm showed that a machine using quantum technology, where the data is stored on individual atoms rather than pieces of silicon, could do the factoring. And the National Security Agency, the centre of US spying technology, jumped on the finding. That same year, it began to pour vast amounts of money into the construction of a quantum computer. That construction might be a work in progress for a while yet.
Or it might not. Something interesting happened ten years on from Shor's breakthrough: the cash injections began to level off. That might be because the NSA has quietly employed the kid down the block who worked out how to factor large numbers; maybe it now knows how to break into every encryption on the planet, and no longer needs a quantum computer. Or it may be that after a decade of tightly focused research, the world's best quantum computer was still laughably primitive; perhaps the NSA simply considers a useful quantum computer unattainable.
Or perhaps it now has one.
Whatever the truth about the quantum computer, its existence and its likely capabilities, one thing is emerging as an inevitable truth. The only data that is protected from this machine's prying eyes, the only data that is guaranteed to be safe for the next fifty years, is data that has been encoded via quantum cryptography, which uses the laws of physics to hide information in photons of light. The meeting I attended at the Bank of England was a first attempt to get the banks to talk to quantum cryptography researchers; the two cultures are coming together to find the best way to bring the strange nature of the quantum world to bear on the economies of nations.
There is much that is uncertain about the future; our energy sources, the stability of sovereign states, the numbers of next week's lottery. But the quantum revolution, where we put the awesome powers of atoms and photons to work, is a certainty. In fact, it's already here.
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