By using keys that are generated using quantum particles, the transmission of data can be guaranteed by the very laws of physics, according to researchers at the Free University of Brussels (ULB) in Belgium and the Institute of Photonic Sciences in Barcelona in Spain. The laws of quantum mechanics state that observing a particle in its quantum state actually modifies that state, which means that in cases where quantum particles are used as keys in the transmission of data, ‘spying’ can be easily and immediately detected.
From New Scientist:
“NOBODY understands quantum mechanics,” lamented Richard Feynman. But Anton Zeilinger at the University of Vienna aims to prove him wrong. His research group has demonstrated the futuristic phenomena of quantum teleportation and quantum encryption, and these successes have encouraged Zeilinger to search for the essence of quantum mechanics–the irreducible kernel from which everything else flows. He believes that he has found it. If he is right, all the mysteries of the quantum world will turn out to be inescapable consequences of a single, simple idea.
To the question, “Why does the world appear to be quantised?” Zeilinger replies, “Because information about the world is quantised.”
Until now, scientists have thought that the process of erasing information requires energy. But a new study shows that, theoretically, information can be erased without using any energy at all. Instead, the cost of erasure can be paid in terms of another conserved quantity, such as spin angular momentum.