Los Alamos develops quantum crypto system that uses photons
Chappell Brown, writing for EE Times reports " Engineers at Los Alamos National Laboratory have developed what they believe is a practical quantum cryptographic system. The system features two portable units that can encrypt and decrypt information transmitted via photons.
Experiments have shown that encryption keys can be sent via free-space transmission at distances of up to 6 miles. The system could be used to ensure safe communications between satellites.....
Quantum cryptography uses the fundamental law of quantum mechanics: Any observation of a system changes its state.
Since photons are elementary particles, they are subject to the law.
If a third party attempts to "tune in" to the encrypted transmission, the quantum state of the photons will change, allowing the eavesdropping to be detected.
