Reid's work has focussed on the fundamental tests of quantum mechanics, including of the Einstein-Podolsky-Rosen paradox and Bell's theorem, based on parametric down conversion and quantum optics. On working with squeezed states of light in the 1980s, Reid thought of a way to test for the original Einstein's entanglement, after noting scientists were able to amplify and detect the tiny quantum fluctuations of optical amplitudes. Experiments since have confirmed this mesoscopic type of Einstein's entanglement in a range of environments, which enables a closer to understanding to Schrödinger's cat. Einstein's scepticism about quantum mechanics may lead to an ultra-secure internet suggests a new paper by researchers from Swinburne University of Technology and Peking University. In a landmark publication, Reid's research group outlined Einstein's reservations about quantum mechanics in a phenomenon known as "'spooky' action at a distance". In 1935 Einstein and researchers highlighted a 'spooky' theory in quantum mechanics, which is the strange way entangled particles stay connected even when separated by large distances. In this paper, theoretical proof that such messages can be shared between more than two people and may provide unprecedented security for a future quantum internet is provided for the first time. In the 1990s, scientists realised one can securely transmit a message through encrypting and using a shared key generated by Einstein's strange entanglement to decode the message from the sender and receiver. Using the quantum key meant the message was completely secure from interception during transmission. Sending Einstein's entanglement to a larger number of people means the key can be distributed among all the receiving parties, so they must collaborate to decipher the message, which makes the message even more secure. The report that a secure message can be shared by up to three to four people, opening the possibility to the theory being applicable to secure messages being sent from many to many. The message will also remain secure if the devices receiving the message have been tampered with, like if an iPhone were hacked, because of the nature of Einstein's spooky entanglement. Discovering that it can be applied to a situation with more parties has the potential to create a more secure internet – with less messages being intercepted from external parties.
