Brute forcing a 256 bits cryptographic code without any known flaws (like WPA2 AES) means that they should test at worst 2^256 keys and average 2^255 (~ 10^76) keys.
Letís say that they are using a new nVidia GPU with 1000 stream processors running at 10 GHz
That is 10^13 instructions per second
Now with their magical software they can check 1 key per instruction.
So, they can check 10^13 keys per second
Even with 1 billion of those GPU (10^9) they can "only" calculate 10^22 key per second (.
At that rate, they need 10^51 seconds which is 10^43 years.
As a reference, the estimate age of the universe is 10^14 years.