What a cool word - "cryptosystems" - which gets used repeatedly in this article about how mathematicians and computer security specialists are trying to keep ahead of the anticipated arrival of quantum computing in 10 or so years time:
“I’m genuinely worried we’re not going to be ready in time,” says Michele Mosca, co-founder of the Institute for Quantum Computing (IQC) at the University of Waterloo in Canada and chief executive of evolutionQ, a cyber-security consulting company.And how about this science fiction sounding explanation of one of the potential replacements for current public key encryption methods:
It will take years for governments and industry to settle on quantum-safe replacements for today’s encryption methods. Any proposed replacement — even if it seems impregnable at first — must withstand multitudes of real and theoretical challenges before it is considered reliable enough to protect the transfer of intellectual property, financial data and state secrets.
“To trust a cryptosystem, you need a lot of people to scrutinize it and try to devise attacks on it
and see if it has any flaws,” says Stephen Jordan, a physicist at the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland. “That takes a long time.”
One such system is lattice-based cryptography, in which the public key is a grid-like collection of points in a high-dimensional mathematical space. One way to send a secret message is to hide it some distance from a point in the lattice. Working out how far the encrypted message is to a lattice point is a difficult problem for any computer, conventional or quantum. But the secret key provides a simple way to determine how close the encrypted message is to a lattice point.The only movie I can recall which was specifically about modern encryption was Sneakers, which I found rather dull and completely forgettable.
Seems to me there must be a good speculative but plausible story to do with quantum computing and security failure, but I doubt that it's been written.