Quantum Cryptography: A New Telecommunications Method

Quantum Cryptography: A New Telecommunications Method

Group 7

Jonathan Bull, Justin Jones, and Ashley Robinett

Key Words: Classical Cryptography, Quantum Cryptography, Quantum Physics, Photons, Eavesdropping, Heisenberg’s Uncertainty Principle

Quantum cryptography is a way for two parties to exchange an enciphering key over a private channel with complete communication security. Unlike traditional cryptography, quantum cryptography uses infinitesimal photons of light to destroy even the most sophisticated of computer eavesdropping schemes devised by the best of hackers. If the data is tampered with by a would-be hacker, the sender and the receiver will know immediately. With this new way of diverting computer crooks, business organizations will be able to transfer sensitive information without fear of having it intercepted by a third party.

Quantum cryptography was first envisioned in the 1970’s by Stephen Wiesner. Wiesner theorized that if Heisenberg’s Uncertainty Principle could be harnessed, the innately volatile character of quantum matter could be exploited to encrypt computer communications. According to Wikipedia, an online encyclopedia, “In quantum physics, the Heisenberg Uncertainty Principle states that one cannot assign, with full precision, values for certain pairs of observable variables, including the position and momentum, of a single particle at the same time even in theory. It furthermore precisely quantifies the imprecision by providing a lower bound (greater than zero) for the product of the standard deviations of the measurements.” As put by Hoi-Kwong Lo, the uncertainty principle asserts that, “merely looking at matter at (a quantum) level will automatically change it.” Based on this principle, Wiesner hypothesized that quantum physics—arguably one of the most confusing subjects in the natural world—could be used to confound cyber-thieves. The traditional method of encryption uses mathematical techniques. As of now, these techniques are valid and useful, but with the development of new mathematical theorems, they will be obsolete. Quantum cryptography relies on a natural law that will never be outdated or superseded.

According to Wikipedia, “Because entangled quantum states are, in the real world, rarely usefully stable, there is a serious practical problem in keeping them entangled long enough to meet the needs of real world interaction between correspondents.” When the first prototype was developed in 1989, information could only be transmitted over a distance of thirty-two centimeters—not exactly a workable distance. Wikipedia further explains, “The first commercial applications of quantum cryptography have thus a limited reach of one hundred kilometers maximum.”

Not until this year did Professor Hoi-Kwong Lo of the University of Toronto conduct a successful experiment proving that quantum encryption is commercially viable. A University of Toronto article regarding Lo’s experiment explains the science of the matter. “In quantum cryptography, laser light particles (photons) carry complex encryption keys through fiber optic cables, dramatically increasing the security of transmitted data…The technique varies the intensity of photons and introduces photonic ‘decoys,’ which are transmitted over a fifteen 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 that the data has been tampered with.”

In an article by Nicolle Wahl on the University of Toronto website, it is stated, “For governments and corporations in the business of transmitting sensitive data such as banking records or personal information over fiber optic cables, (quantum cryptography) offers the protective equivalent of a fire-breathing dragon.” Professor Lo testified, “Quantum cryptography is trying to make all transmissions secure, so this could be very useful for online banking, for example.”

The benefits to quantum cryptography are many and evident. Having a connection that is guaranteed to be secure allows businesses a measure of freedom previously unknown. Presently, extreme caution and special care is taken to keep private records and information confidential and away from the sneaky fingers of hackers. With quantum cryptography, businesses would be able to send and receive such information with more ease.

A business using quantum cryptography would also be able to offer its customers/clients the peace of mind that there personal information was in the safekeeping of this virtual “fire-breathing dragon.”

This technology can be implemented right away, as Lo’s experiment was done with a commercial device. Online security has taken another huge step forward!

Quantum cryptography is technology’s newest offer to the world of computer security and it is making the world of business a safer place. Thanks to the efforts of Professor Lo of the University of Toronto and previously to Stephen Wiesner, we are now on the cutting edge of communication security. Not only is it virtually impossible for hackers to penetrate the system, even if they attempt to eavesdrop on transmitted data, both the sender and receiver are immediately notified and are able to take any actions necessary. With cybercrimes on the rampage, modern researchers are constantly devising new ways for the everyday users of communication technology to be safe, and for that we are thankful.

References

Brassard, Gilles. (1994). A Bibliography of Quantum Cryptography.

Retrieved March 5, 2006, from http://www.cs.mcgill.ca/~crepeau/CRYPTO/

Biblio-QC.html.

Ekert, Artur. (1995). What Is Quantum Cryptography?

Retrieved March 5, 2006, from http://www.qubit.org/library/intros/crypt.html.

Hall, Joseph. (2006). Prof says there’s no hacker he can’t foil. Toronto Star.

Retrieved March 5, 2006, from

http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/

Article_Type1&c=Article&cid=1140648614823&call_pageid=970599119419

Wahl, Niccole. (2006). Hackers Beware! New technique uses photons, physics to foil

codebreakers.