So as you may have heard, the Adobe user database with 130 million records was leaked recently. I want to find out what password I used for the Adobe account I created to make sure that I'm not using it anywhere else. But how do I decrypt the Triple DES ECB-mode encrypted password? Is there a way to do this without knowing the Adobe Cipher Key? Is there a way to get the Cipher Key?
The encryption key was never published and triple DES itself is strong enough to not brute force, so you have to use some of the other mistakes to attempt to recover your password.
Your options are: exploit the fact that they used ECB and use the hints.
To do this you will find your encrypted password and see if other users had the same block. For example, say your encrypted password blocks were (shortened for simplicity):
87bef a31cd and you find another user that had
87bef 37cfe you know that the first 8 characters (since DES blocksize is 8 bytes) of your password are the same as the first 8 of the other user. Then you can use their hint to help figure your password out. Same process applies to subsequent blocks.
A very good explanation can be found at this url: http://nakedsecurity.sophos.com/2013/11/04/anatomy-of-a-password-disaster-adobes-giant-sized-cryptographic-blunder/
The idea is exactly what mikeazo said in an other answer.