[BBray_T1296]

Assuming 3.4GHz and 4 cores, (though this use of clock speed is entirely incorrect)
Let's just pretend we can sail along at 13.6 billion attempts per second
96^20 = 4.42 E39 possible combinations
There are 31557600 seconds in a year.
The universe is ~13.8 Billion years old

4.42 E39
(~3.16E7 * 1.36E10 * ~1.38E10)
Let's just say it would take a while.

So long, in fact, the entire lifetime of the universe from the Big Bang up until today, would be able to occur 750 Billion times before every combination was tried.