Last Friday night, I was at a barby having this fascinating conversation with a friend* about the history of Cryptography (as you do). It reminded me about a scientist I'd read about and his theories including 'Cellular Automata'...that very complex systems can be generated by simple building blocks.
Delicious and fascinating stuff...all online:
"A New Kind of Science" by Stephen Wolfram.
*Pip Jones - who heads up VictoriaReal here in Sydney...tasty new website at: http://www.victoriareal.com.au