Whit Diffie has some more info, including a clarification, on the differences between Hagelin and rotor machines: Forwarded message: To: tcmay@netcom.com (Timothy C. May) From: whitfield.diffie@Eng.Sun.COM Date: Tue, 12 Oct 1993 at 08h00 Subject: NSA Can Spend a Billion on a Computer Minor technical point
The Harvest machine was particularly good at brute force breaking of Hagelin-type rotor machines, the "DES of its day"
Hagelin machines aren't considered rotor machines even though their main moving elements do rotate. Rotor machines had rotating elements that were wired wheels implementing table look-ups, i.e., S-boxes. The six wheels in a Hagelin machine merely have setable bits around their edges. The are in effect pieces of binary key that rotate --- much like the C and D registers in DES. Feel free to redisseminate this if you like. Whit