A NEW distance record for transmitting entangled photons over free space has brought the prospect of using quantum cryptography for secure satellite communication a step closer.
Entanglement, one of the strange phenomena of quantum physics, has tempting uses in communications. Entangled particles are linked to each other, and remain so even when separated by great distances. Quantum cryptography keeps messages safe by sharing entangled photons between two sites to establish encryption keys for coding and decoding a message. Measure a property of an entangled photon at one site and you instantly know the corresponding property of its distant partner.
Using…
