3 ms·

I always thought it was such an elegant design. Shame (or fortunate rather) that the Allies were able to break it so quickly.

thatswrong0 5y ago
(Gross oversimplification but..) One seemingly innocuous bug deep in the encryption "library", that no letter could map to itself, plus a bit of social "engineering" in taking advantage of the fact that messages often included the same text (e.g. "heil hitler") often in the same position, with a smattering of German complacency and arrogance assuming that their machine was uncrackable. Pretty funny that the lessons learned here are still relevant to this day.
- beachy 5y ago
  My bank disallows "simple" pin codes like 1234, 1111, etc. This even further reduces the difficulty of guessing pin codes.
legitster 5y ago
Even after it was "broken", it took a lot of work to decrypt - sometimes allies were months the German messages.
tialaramex 5y ago
The German assumption, throughout the war, was that Enigma could be cracked but it was probably too hard so the Allies would not try. You can see that not all of the German Military was as easily sold on this belief, because some forces stayed with a relatively basic machine while at the end the U-Boats were using a four rotor machine and much stricter rules to reduce attack surface. Ironically they were undone by their need to transmit and receive very succinct messages in order to spend less time on the surface where they were vulnerable. Germany was in particular unaware that Poland - understandably nervous of an increasingly combative Germany years before the war started - had cracked Enigma when it was a commercial system in the 1930s. This knowledge was transmitted to the British in 1939, and the cryptanalytic team who did it began leaving Warsaw before (inevitably) Germany invaded in September. There's a small memorial to the Polish code breakers at Bletchley Park, it's not exactly on the main tour, so if you care ask someone when you're there to tell you where. People who were there suggest it made maybe 12 months difference, specifically to Enigma (Bletchley Park did other less famous cryptographic work) which is a pretty significant difference. Enigma is interesting because it's so famous and yet it's completely the wrong design, and this is exactly the era when people stop doing that. The Colossus computer, also at Bletchley park, is to break the Lorenz cipher not Enigma, because Lorenz is a much more "normal" design to us today. It's a Vernam stream cipher, it encrypts bit streams and it merely so happens that those bit streams are Morse code. You could perhaps say Lorenz is a (distant) ancestor of, say, ChaCha20. In contrast Enigma looks like cryptography from previous centuries, it encrypts symbols, one symbol in -> one encrypted symbol out. No letter on your Engima machine's keyboard representing the symbol you wanted? Say it in words or don't encrypt it. This is in some ways more practical (Enigma was actually used with radio traffic, but in principle you could send letters, or encrypt your diary, or whatever) but in cryptographic terms it's a complete nightmare.
- nullc 5y ago
  > Enigma is interesting because it's so famous and yet it's completely the wrong design, The allies sigaba was basically the same design-- but it lacked the reflector so letters could encrypt to themselves. The down side of this is that it needed a complex mechanism to reverse the signal flow when switching between encrypting and decrypting. (there were many other improvements in sigaba, but the big one that made it hard to crack was eliminating that one weakness) > You could perhaps say Lorenz is a (distant) ancestor of, say, ChaCha20. The first cracked Lorenz message happened because a signal re-transmission was needed so they sent the same message again using the same keystream-- except it wasn't the same message: the operator abbreviated a word, shifting the following characters. So they effectively reused the same keystream with different messages. Systems using stream ciphers (e.g. CTR mode) are still falling to this today. Seems we haven't learned that much after all!

thatswrong0 5y ago

(Gross oversimplification but..) One seemingly innocuous bug deep in the encryption "library", that no letter could map to itself, plus a bit of social "engineering" in taking advantage of the fact that messages often included the same text (e.g. "heil hitler") often in the same position, with a smattering of German complacency and arrogance assuming that their machine was uncrackable. Pretty funny that the lessons learned here are still relevant to this day.

beachy 5y ago
My bank disallows "simple" pin codes like 1234, 1111, etc. This even further reduces the difficulty of guessing pin codes.

legitster 5y ago

Even after it was "broken", it took a lot of work to decrypt - sometimes allies were months the German messages.

tialaramex 5y ago

The German assumption, throughout the war, was that Enigma could be cracked but it was probably too hard so the Allies would not try. You can see that not all of the German Military was as easily sold on this belief, because some forces stayed with a relatively basic machine while at the end the U-Boats were using a four rotor machine and much stricter rules to reduce attack surface. Ironically they were undone by their need to transmit and receive very succinct messages in order to spend less time on the surface where they were vulnerable. Germany was in particular unaware that Poland - understandably nervous of an increasingly combative Germany years before the war started - had cracked Enigma when it was a commercial system in the 1930s. This knowledge was transmitted to the British in 1939, and the cryptanalytic team who did it began leaving Warsaw before (inevitably) Germany invaded in September. There's a small memorial to the Polish code breakers at Bletchley Park, it's not exactly on the main tour, so if you care ask someone when you're there to tell you where. People who were there suggest it made maybe 12 months difference, specifically to Enigma (Bletchley Park did other less famous cryptographic work) which is a pretty significant difference. Enigma is interesting because it's so famous and yet it's completely the wrong design, and this is exactly the era when people stop doing that. The Colossus computer, also at Bletchley park, is to break the Lorenz cipher not Enigma, because Lorenz is a much more "normal" design to us today. It's a Vernam stream cipher, it encrypts bit streams and it merely so happens that those bit streams are Morse code. You could perhaps say Lorenz is a (distant) ancestor of, say, ChaCha20. In contrast Enigma looks like cryptography from previous centuries, it encrypts symbols, one symbol in -> one encrypted symbol out. No letter on your Engima machine's keyboard representing the symbol you wanted? Say it in words or don't encrypt it. This is in some ways more practical (Enigma was actually used with radio traffic, but in principle you could send letters, or encrypt your diary, or whatever) but in cryptographic terms it's a complete nightmare.

nullc 5y ago
> Enigma is interesting because it's so famous and yet it's completely the wrong design, The allies sigaba was basically the same design-- but it lacked the reflector so letters could encrypt to themselves. The down side of this is that it needed a complex mechanism to reverse the signal flow when switching between encrypting and decrypting. (there were many other improvements in sigaba, but the big one that made it hard to crack was eliminating that one weakness) > You could perhaps say Lorenz is a (distant) ancestor of, say, ChaCha20. The first cracked Lorenz message happened because a signal re-transmission was needed so they sent the same message again using the same keystream-- except it wasn't the same message: the operator abbreviated a word, shifting the following characters. So they effectively reused the same keystream with different messages. Systems using stream ciphers (e.g. CTR mode) are still falling to this today. Seems we haven't learned that much after all!