Canadian researchers said they have developed a technique that protect sensitive data transmitted via fiber-optic cables. Researchers at the University of Toronto developed the technique for governments and corporations in the business of transmitting sensitive data such as banking records or personal information, and they said it offers the protective equivalent of a fire-breathing dragon.
“Quantum cryptography is trying to make all transmissions secure, so this could be very useful for online banking, for example,” said lead researcher Hoi-Kwong Lo, of the university’s Centre for Quantum Information and Quantum Control. “The idea can be implemented now, because we actually did the experiment with a commercial device.”
Reporting in the Feb. 24 issue of Physical Review Letters, Lo and colleagues describe the first experimental proof of a quantum decoy technique to encrypt data over fiber optic cable.
In quantum cryptography, laser light particles (photons) carry complex encryption keys through fiber-optic cables, dramatically increasing the security of transmitted data.
Conventional encryption is based on the assumed complexity of mathematical problems that traditional computers can solve. Quantum cryptography is based on fundamental laws of physics and on Heisenberg’s Uncertainty Principle, which asserts that the act of merely observing a quantum object alters it.
The technique varies the intensity of photons and introduces photonic decoys transmitted over a 15-kilometer telecommunication fiber. After the signals are sent, a second broadcast tells the receiving computer which photons carried the signal and which were decoys. If a hacker tries to eavesdrop on the data stream to figure out the encryption key, the mere act of eavesdropping changes the decoys – a clear sign to the receiving computer the data stream has been disturbed.
