Quantum Cryptography

Quantum Cryptography promises unbreakable codes. But are you ready to tell your secrets yet?

Posted by Tormod Guldvog
13 September, 2001 04:09:35

Since the invention of writing, there has been a need to make sure certain messages could only be understood by the right recipient. A great number of more or less elegant tricks have been used.

The problem with all codes, however, is that they can be cracked. One of the most famous examples is the story of how the British cracked Hitler's Enigma code during World War II.

Cryptography is very important on the Internet. PGP (Pretty Good Privacy) offers surfers a simple way to encrypt their mail. Although it is hard to break, it is not unbreakable.

But there is a new kid on the block: Quantum cryptography. By using photons as messengers, it is now possible to create messages which are impossible to intercept. In fact, if someone tries to read them, the code magically vanishes!

This week we present various views on what quantum cryptography is, and how it actually works.

And don't forget to take the poll!

Related Links

What is Quantum Cryptography?
http://www.qubit.org/intros/crypt.html
This is an excellent presentation by the Centre for Quantum Computing.�cryptograph

Quantum Cryptography in Norway
http://www.fysel.ntnu.no/Optics/qcr/
This page presents current events in quantum cryptography in Norway. Their research center is located half a mile from the Hypography headquartes at Kjeller.

You'd Have to Break the Laws of Physics to Break This Code
http://www.aip.org/releases/2000/release03.html
A rather bold proposition, but this press release explains why Quantum Cryptology is impossible to break.

Web seminar: Quantum Computation and Information Theory
http://www-brims.hpl.hp.com/websems/quantum/lo/sem.html
This is a recorded version with slides from a presentation on quantym cryptography. You need RealAudio to use it, though.

Introduction to Cryptography
http://www.ssh.fi/tech/crypto/intro.html
This is an introduction to cryptography in general. It provides a good presentation of different aspects of cryptography, and touches on quantum cryptography as well.

Quantum Cryptography
http://matu1.math.auckland.ac.nz/~king/Preprints/book/quantcos/aq/qcrypt.htm
This is the complete text of an article published in Scientific American. It is rather long, but it will give you a good insight into quantum cryptography.

Physicists Triumph at Guess My Number
http://www.qubit.org/intros/gmn/gmn.html
This is an entertaining demonstration on how quantum encryption works. It gets a bit technical in the end.

Quantum Cryptology
http://fog.hpl.external.hp.com/techreports/97/HPL-97-151.html
This page has a link to a PDF document which in fact is a book on quantum cryptology. Recommended reading!

Quantum Confidential
http://www.newscientist.com/ns/19991002/quantumcon.html
This is a feature article on cryptography from New Scientist. It is written by Simon Singh, author of "The Code Book".