Originally Posted by snowmanwithahat
There's a guy I've been talking to who's running a quad-GTX 295 server for cracking WPA passphrases. He's saying it's pushing 80,000 keys a second... Very impressive and realistic considering my GTX 285 which is extremely overclocked is putting ou 15,000 keys a second.
That's cool and all, but 80,000 isn't nearly enough.
If we have an 8 letter phrase with letters a-z and numbers 0-9, that's 36 characters. With 8 characters, we have 36^8 different keys. That's roughly 2.8E12. Divide that by 80,000 per second and we are looking at roughly 400 days.
And that's not even considering special characters (!,@,#,$,%,etc.) and different letter cases (a,A,b,B,etc.). Throw those in there and you're nowhere near cracking an 8 character key.
Of course I am talking about brute force. If you can make educated guesses (i.e. eliminate characters) then you will have a power law decay of required guesses. Also, again, I am talking about pure brute force decryption.