In what could eliminate the risk of sensitive information falling into the wrong hands, scientists have discovered a new way to send secure messages which can only be read by someone at an agreed location.
An international team has developed a new "quantum communication" process that delivers unprecedented security - in fact, it ensures that even if an encryption password falls into the wrong hands, a secure message can only be seen by a recipient at the right location.
Team leader Prof Robert Malaney at the University of New South Wales said: "This takes communications security to a level that hasn't previously been available. With this process you can send data to a person at a particular location.
"If they are not at that location the process would detect that and you can stop the communication. This is a new application that you can deploy on current and emerging quantum networks."
It opens up a range of new information security applications for both fibre and wireless communication networks. There would be many industries and organisations, banks for example, that would be interested in delivering information content in the sure knowledge a recipient is at an agreed upon location."
According to the scientists, the system works by sending paired "qubits" - particles such as photons, which have been manipulated to contain specific quantum information - over a fibre optic or wireless network to a recipient.
The recipient must send a return message, using information from the decoded qubits, to a number of reference points to open up a secure channel. Because quantum networks operate at the speed of light and quantum information cannot be copied, the time to return the message can be accurately measured, ensuring that it has come from only one possible place, say the scientists.
The concept, which also has potential applications in the intelligence community, e-commerce and digital content distribution, has been published in the latest edition of the 'Physical Review A' journal.