AN AEROPLANE has beamed quantum encryption keys to a station on the ground, paving the way for an ultra-secure global communications network.I have criticized Quantum cryptography on this blog many times, such as in Aug 2011, Jun 2011, May 2011, Apr 2011, Sep 2010, May 2010, Jan 2010, and Oct 2008. It is the biggest scam in modern physics.
Quantum key distribution (QKD) uses photons polarised in two different ways to encode the 0s and 1s of an encryption key. The laws of quantum mechanics ensure the transmission is secure, as any attempt to intercept the key disturbs the polarisation - a tip-off to the receiver that the key has been seen and should be discarded. ...
Back on the ground, researchers at the European Space Agency's Optical Ground Station in Spain's Canary Islands broke the distance record for quantum teleportation, which uses quantum entanglement to make message transmission more secure (Nature, doi.org/jbs). They teleported quantum states over 143 km, breaking a record of 97 km reported earlier this year.
There are three big problems with quantum cryptography: (1) it assumes equipment idealizations that can never be met in practice; (2) the laws of quantum mechanics do not ensure any security; and (3) even if the theory and practice could do everything promised, the method has no practical utility.