Quantum Cryptography & Simulation
"While classical cryptography employs various mathematical techniques to restrict eavesdroppers from learning the contents of encrypted messages, in quantum mechanics the information is protected by the laws of physics. In classical cryptography an absolute security of information cannot be guaranteed. The Heisenberg uncertainty principle and quantum entanglement can be exploited in a system of secure communication, often referred to as 'quantum cryptography'. Quantum cryptography provides means for two parties to exchange a enciphering key over a private channel with complete security of communication." -Artur Ekert

     In Spring 1997, I took a wonderful 2-credit class entitled Internet Security from professor Darrell Long. Truly, the course should have been more appropriately named CryptoClass, for the main focus of study during the 8 week excursion was various cryptosystems, mathematical fundamentals of cryptography, cryptographic protocols and more of the like. Class culmination was to choose some aspect of cryptography (ie, protocols, applications, etc.) and use it as the basis for a short research paper. I discovered a topic with the hep name of Quantum Cryptography.
     The best overviews of Quantum Cryptography I have seen so far are in two magazine articles recommended by Bruce Schneier. Schneier's book, Applied Cryptography, itself contains a smaller, more concise overview of QC. Also quite worthy of note is a paper by Artur Ekert, one of the early formulators of today's Quantum Cryptography.
     Soon to be added to this list of admirable literature will be my own research paper, ;), Fast Forward: Quantum Cryptography, written for Darrell's class.

  • Charles H. Bennet, Gilles Brassard and Artur K. Ekert, "Quantum Cryptography", Scientific American, v. 267, n. 4, Oct 1992, pp. 50-57

  • C. Zimmer, "Perfect Gibberish", Discover, v. 13, n. 12, Dec 1992, pp. 92-99

  • Bruce Schneier, Applied Cryptography, John Wiley & Sons, 1996, ch. 23.16

  • Artur Ekert, "What is Quantum Cryptography", http://eve.physics.ox.ac.uk/NewWeb/Research/crypto.html

         As an aid to understanding how quantum cryptography works, I wrote a program that would simulate a quantum cryptosystem based on two non-commuting observables - cryptosystem A as mentioned in the paper by Ekert.

    last update: 19th August 1997
    Jeremy Avnet .:. brainsik@cats.ucsc.edu