"Yeah, okay, well - if you had a machine like that, then any given preset could be represented by a number - a string of symbols. And the tape that you would feed into it to start the calculation would contain another string of symbols. So it's Godel's proof all over again - if any possible combination of machine and data can be represented by a string of numbers, then you can just arrange all of the possible strings of numbers into a big table, and then it turns into a Cantor diagonal type of argument, and the answer is that there must be some numbers that cannot be computed." (pg. 20)

"Ultra and Magic are more symmetrical than not. In each case, a belligerent Power has developed a machine cypher which it considers to be perfectly unbreakable. In each case, an allied Power has in fact broken that...