A theoretical computer system operating at the atomic and subatomic level with vastly increased raw processing power. This area of computing is currently undergoing much research and development. A useful implementation may be years or decades away.
Miniaturization in chip design has allowed for information processing to occur at faster rates, however quantum computing could expotentially increase computing power to unheard of speeds. Such a computer would find attacking encrypted communications much easier and quicker than conventional computers.
Quantum encryption is not the same as quantum computing although they have related areas. Quantum cryptography uses light particles known as photons to protect information rather than random-number keys. With this kind of cryptography enabled eavesdropping becomes physically impossible.
- Slate article on the current difficulty of Quantum Computing
- Quantum Computing from Caltech
- What is Quantum Information Processing?
- Quantum Theory