This is how long it would roughly take to bruteforcing your way to an AES128 xbox360 key (key to decrypt xex)
(if you would/could calculate even more precise, one would find out it would probably take even longer then the numbers below)
5,395,141,535,403,007,094 million years
5,395,141,535,403,007 billion years
(based on the max nr of seconds per key being 1.7 x 10^32)
The key you want to find uses AES256 which is twice as long
and 128 exponentially greater then the 360 key.
To illustrate the complexity of AES256;
Originally posted by another user
A device that could check a billion billion (10^18 ) AES keys per second would require about 3×10^51 years to exhaust the 256-bit key space.
Needless to say this is simply not feasible and with current technology cannot be accomplished.