[ptha]

Interestingly from: https://en.wikipedia.org/wiki/Enigma_machine#History

"An estimated 100,000 Enigma machines were constructed. After the end of World War II, the Allies sold captured Enigma machines, still widely considered secure, to developing countries".

I'm sure they were quite happy to sell Enigma and also decrypt their communications for nearly another 30 years.

[arethuza]

Another interesting thing to note is that the Soviets knew fine well that the UK could decrypt German codes from their spies at Bletchley Park.

[anovikov]

If the Enigma machines were operated properly, they could never be broken. Breaking them were a result of German lack of discipline and irresponsibility, not machine's weakness (maybe a simple inscription on the cover of machine in the bold letters would help though, machine designers just expected too much from their enlisted, barely literate operators).

[gshubert17]

Not never. One of the "features" of the Enigma was that a plaintext letter could never be encrypted to itself. An 'A' going in could come out as any other letter, except 'A'. German information security policies were generally pretty good. There were lapses, of course, and some of these were used to form cribs for a known plaintext attack on encrypted messages. But Enigma was/is not invulnerable.

People found a couple encrypted Enigma messages after World War II. Here is a note from a group of people using modern computers and brute force to decrypt them:

http://www.enigmaathome.net/forum_thread.php?id=318

[anovikov]

yes of course, by 'never' i mean 'not in the WWII timeframe'.