Hi E B,

I am not quite sure what your code is doing as it is not running on my computer like that. I have modified it and I hope that it is doing wha you are trying to achieve:

chars = CharacterRange["a", "z"];
keys = DeleteDuplicates[Flatten[Table[a <> b <> c, {a, chars}, {b, chars}, {c, chars}]]];
Quiet[Map[If[Decrypt[#, encoded] === $Failed, , Print[#]] &, keys]];

It does run quite a while, but only returns the one string I used to encrypt the data. (I ran it on a three letter string.)

Cheers, Marco

PS: The funny thing is that when I used ParallelMap to accelerate it, the code did not work.

That is quite curious. I only used:

encoded = Encrypt["abc", "This is a test."]

for my example and it seems to work fine. As you see I also used Decrypt in my program. I ran your program and can now reproduce that. It looks a bit funny indeed. It even "cracks" your complicated password with four simple three letter combinations.

If you run

chars = CharacterRange["a", "z"];
keys = DeleteDuplicates[
   Flatten[Table[a <> b <> c, {a, chars}, {b, chars}, {c, chars}]]];
encoded = ToFileName[$TemporaryDirectory, "encoded"];
Encode["~/Desktop/test.m", encoded, "abc"]
Map[If[Get[encoded, #] === $Failed, , Print[#]] &, keys];

it recovers the password but finds three additional ones that work. I am not sure whether this is the intended behaviour.

Cheers,

Marco