Section 2.12, due November 23

Difficult: I do not fully understand the discussion of the permutations used to break Enigma. The text mentions that letters never mapped to themselves in the machine, but the 1 cycles in the examples seem to indicate that they could. Also, how exactly did deciding the cycles reduce the problem to a substitution cipher? The initial keys were still quite random, so it seems that there would be trouble figuring out the permutations you need. How many messages were needed to work out which permutations you were looking at for a day?

Reflective: This is just an extremely interesting section. I enjoyed learning more about the enigma machines. I had no idea that the British then used them to spy on former colonies, that is quite interesting. Good to see governments haven't changed quite so much as we might think. I was disappointed that the links you posted did not work for me, so I could not read the extra information from the NSA.