Well, also its susceptibility to both known-plaintext attacks and statistical analysis, though it depends a bit if you're talking about the army version of the

Well, also its susceptibility to both known-plaintext attacks and statistical analysis, though it depends a bit if you're talking about the army version of the enigma or the navy version. Also until very late versions, the machine couldn't map a letter to itself, which was another critical vulnerability. The actual keyspace was around 76 bits [1], which is fairly respectable, particularly for the mid-20th century. Much of the weakness was, in fact, the result of the Enigma being an early device in a nascent technological field -- ie, the result of failures in the Enigma's design, as well as procedures surrounding its operation (not just operator error; for example, Polish cryptanalysts used the procedural repeating of the rotor setting initialization (it's conceptually similar to an initialization vector in modern crypto) to break early versions of the machine as early as 1932. [1] https://en.wikipedia.org/wiki/Enigma_machine#Details https://en.wikipedia.org/wiki/Enigma_machine#Details