The Enigma was a very advanced cipher at the time, even though it was eventually broken. Not that long ago, if you think about it. Which makes you wonder if a slightly more advanced civilization can visualize and take apart MD5, SHA-1 and AES just as easily as we can the Enigma.
Except we have taken apart md5, sha1 and working on AES... cryptosystems are made to be broken. We haven't proven if a one way function exists. When we can do that then we can move forward in encryption.
Oh, I meant that the whole thing was not too long ago, WW2 and everything, in the scale of human progress. (I know all about Bletchley -- crypto is part of my day job :-)
The U-505 Submarine exhibit at the Museum of Science and Industry in Chicago, which is extremely detailed overall, features a few sub-exhibits on Enigma machines including simulators, which you can experiment with, use, and encode and decode messages for/from other patrons.