[Cryptography] Possible reason why password usage rules are such a mess

[Jerry Leichter]

>> Bear in mind that military crypto has a much longer history, numbering in centuries. Whereas civilian crypto up-ticked in the 80s (Unix delivered DES as an early mistake) and only became really important in the 90s. All the expertise was initially military - even the guys who were involved in Unix security eg Morris were connected to military and IC.
> 
> I'd like to know more about this Unix DES mistake; I thought it was merely a one-rotor box (with added salt).
The one-rotor box was the original crypt command.  iang will certainly answer with his take on it, but I suspect the "DES mistake" was, in NSA's view, that DES was delivered as a software solution to a broad audience.  NSA at the time believed in hardware implementations and was hard at work trying to control the "leakage" of good cryptography into the general community.
                                                        -- Jerry