Mitsubishi and Hokkaido University have advanced the science of quantum cryptography by sending data encrypted using the states of photons over a 200 meter length of optical fiber. Quantum crypto, first demonstrated in the US in 1989, uses the states of photons used to send a message as the cryptolological key and relies on the fact that observing the state of a subatomic particle actually changes its state, thus making any message interrupted in transit unreadable. The technology is important because it promises optical network security that is independent of crypto algorithms and virtually indecipherable. It is also interesting because the advent of quantum computers could provide, when they come to market, the computing power to crack, through brute force, any message encrypted using conventional mathematical encryption. Quantum cryptography, however, would theoretically produce encrypted materials that could not be cracked even by a quantum supercomputer.
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