Quantum Computing Just Got More Bizarre
You don’t even have to turn it on:
With the right set-up, the theory suggested, the computer would sometimes get an answer out of the computer even though the program did not run. And now researchers from the University of Illinois at Urbana-Champaign have improved on the original design and built a non-running quantum computer that really works.
So now, even turning the machine off won’t necessarily prevent hackers from stealing passwords.
And as long as we’re on the topic of quantum computing, here’s a piece of quantum snake oil:
A University of Toronto professor says he can now use a photon of light to smash through the most sophisticated computer theft schemes that hackers can devise.
EDITED TO ADD (3/1): More information about the University of Illinois result is here.
RC • February 28, 2006 1:48 PM
So the basic concept behind quantum encryption is that intercepted bits are ‘tamper evident’. Intercepting a photon to read its state prevents that state from being handed on to the recipient unaltered.
However, there are ways to intercept such photons with a better than 80% chance of not altering the state of the photon. Add to that the fact that over long distances any type of communication may have bit errors, and the certitude behind quantum encryption disappears. See the link for more info.