[arithmomachist]

Fascinating to see the highest state of the art of pre-digital cryptography, right before it was rendered obsolete. Very evocative that volumes 4-6 were planned but never completed, presumably because the first crop of modern encryption schemes were already outdating theses volumes as they were being written.

I wish the NSA would declassify more records of what it managed to break in the pre-digital era, now that the methods are out of date and the people involved are mostly dead. It would be great for historians to see both what the agency was capable of in that period, and how its methods, together with its successes and failures, shaped history in the early Cold War.