I was playing around with the Encode/Get functions - specifying a key, and found that an encoded package could be decoded with numerous other keys. The below code works on all encoded files that I have tried:

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

The output is usually 4 3-character keys that can be used to decode the package. They vary depending on the key that was given for encoding. I have tried it for other combinations such as 4 characters, 2 characters + digit and it gives other possible keys. It also produces the error (in the messages window): INTERNAL SELF-TEST ERROR: FileNotify|c|305

I am using Mathematica 10 - can anyone replicate this?