Sharing secrets via teleportation

Spy networks and international financial systems may benefit from an advance in teleportation technology developed at the Australian National University.

Researchers there claim to be the first in the world to demonstrate sharing secrets via teleportation using quantum physics. The research has potential to significantly enhance the security of computer systems around the world.

The researchers provided a window on the future of telecommunications by demonstrating the production, disembodiment and successful reconstruction - or teleportation - of a message to a network of participants.

The experiment was conducted by 24-year-old PhD student Andrew Lance and Dr Thomas Symul from the Quantum Optics Group in the ANU Faculty of Science, in collaboration with Prof Barry Sanders from the University of Calgary in Canada.

The research builds on the teleportation work by Dr Warwick Bowen and Dr Ping Koy Lam at the ANU in 2002, when they teleported information using a laser beam.

"This is a much more complex form of information teleportation in the sense that it involves multiple recipients," Dr Lam said.

The researchers used crystals, lenses and mirrors to produce a pair of 'entangled' laser beams that are then used to carry fragile information in the form of quantum states. These cannot be measured or copied, making eavesdropping impossible.

The transmission of the light beams constitutes a secret communication scheme with guaranteed security.

The process of secret sharing is a fundamental part of present day telecommunication, computer and banking practices. Such network communication can be enhanced using the laws of quantum physics to protect the information - a process called quantum state sharing.

"The benefit of this technology is that the encrypted message can only be decoded by a majority of recipients. For example, if an encrypted message was sent to a spy network containing 15 individuals, a minimum of eight agents would be needed to access the message - limiting the chances of the message being infiltrated or deleted by a double-agent," Lance said.

"The system could also have major applications as a fail-safe mechanism in operating systems for the new generation of super-fast quantum computers."