Thanks to the laws of quantum mechanics, quantum cryptography sends information using laser light particles (photons)with encryption keys through fiber optics in order to secure communication.

So, hackers should take note that researchers -- like those at the University of Toronto -- have successfully completed a new technique that could nab eavesdroppers in the future.

Published in the Feb. 24 issue of "Physical Review Letters," their study looked at manipulating the intensity of photons in order to create "decoys" to catch eavesdroppers.

Researchers also expanded the encryption key rate and distance for the technique, using a commercial device, according to Professor Hoi-Kwong Lo, an expert in physics and electrical and computer engineering at the University's Centre for Quantum Information and Quantum Control and the senior author of a new study.

As Lo explains, quantum cryptography is better than today's conventional encryption, because it is based on the laws of physics -- specifically Heisenberg's Uncertainty Principle, which states there can be no full precision of values for pairs of variables including position and momentum for one single particle.

Using this principle, they devised a technique that varies the intensity of photons, creating some photonic decoys, transmitted over a 15 kilometer telecommunication fiber. After signals are sent, a second broadcast tells the receiver which photons carried the signals and which were decoys. If a hackers tries to "eavesdrop" on the data stream to figure out the encryption key, the decoys changes, at which rate the receiver knows the information was tampered with.

"Once consumers become aware of the risks involved in today's encryption which needs to be more secure, quantum cryptography will be the future," Lo said.

But quantum cryptography is not new; it's been under work since 1984 in its theoretical phase and 1992 in its first experimentation. Businesses such as MagiQ Technologies, Inc. and University of Geneva's spin-off company id Quantique, Geneva, are already been marketing commercial quantum cryptographic products.

Moreover, the United States has been researching the technology including the Military's Defense Advanced Research Project Agency as well as such major firms, IBM, NEC, NTT, and Toshiba, who may make commercial products in the future, Lo said.

And the United States has made progress. One such example is creating the world's first quantum cryptographic network called the DARPA Quantum Network in 2004.

Sponsored by DARPA, BBN Technologies worked with Harvard University and Boston University to build and operate the six-node quantum cryptographic network that exchanged secure keys within 10 kilometers between BBN and Harvard.

Today, the secure network has extended to 10 nodes, extending 100 km between the three entities under the streets of Cambridge and Boston, Massachusetts, and equipped with Internet and applications such as web surfing and video conferencing.

But as quantum cryptography is secure, its communication has becoming faster -- 20 times faster -- thanks to BBN Technologies.

The hi-tech research firm confirmed Thursday, that they came up with the technology to provide continuous operation at a 100 million pulses per second after a year of research.

However, in another year or two, that speed may go beyond even 10 billion pulses per second, according to Chip Elliott, principal engineer with BBN Technologies and principle investigator of the project.

BBN researchers worked in collaboration with Colorado-based National Institute of Standards and Technology (NIST), University of Rochester in New York and Moscow Institute of Physics and Technology, under sponsorship of DARPA.

The system uses NIST-developed packaging and cooling technology coupled with the superconducting detector to a standard telecom fiber, operating at a temperature of about 3K without using liquid cryogens.

Whereas the old system used integrated circuits, Elliott explains, it now has a strip of metal and in which a spark of electricity is made when a single photon hits the metal. Upon doing so, it then quickly becomes absorbed allowing for the next photon to hit the metal. BBN's technique now speeds up that process.

So what does this mean for quantum cryptography?

"Until now, quantum cryptography looked a lot like dial-up, it worked but you wished it worked faster, but now it's in the fast lane," Elliott said. "It's also communication cross the city. The Holy Grail is to go coast to coast or under the Atlantic Ocean to Europe -- we want to go as far as you can go."

He explains that while it is unknown rather companies will make the transition from the current system to quantum cryptography, the technology is going beyond protecting e-mail and instant messaging but also to include video conferencing, movie downloads, and telephone conversing.

Research continues to make headway in the field of advancing quantum cryptography, although research firms still look for major funding sources and partners to continue expand the system's distances and security.

This may also be a push-start in the right step in putting back consumer faith into a new form of communication within an atmosphere of evolving technologies and countering hackers.

Email This Article

Related Links
- Cyberwar - Internet Security News - Systems and Policy Issues