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> To crack a password with 70 bit entropy on a MacBook Pro Early 2013 it will take ~6 million years to complete all combinations on Normal complexity. On Interm

> To crack a password with 70 bit entropy on a MacBook Pro Early 2013 it will take ~6 million years to complete all combinations on Normal complexity. On Intermediate complexity it will take ~24 million years and on Advanced complexity it will take ~280 million years to reach all combinations at minimum. If you were cracking a password wouldn't it be significantly faster to use GPU(s) rather than CPUs [1]? If so, why bother mentioning how long it would take on a CPU at all? [1] http://arstechnica.com/security/2012/12/25-gpu-cluster-cracks-every-standard-windows-password-in-6-hours/ http://arstechnica.com/security/2012/12/25-gpu-cluster-crack...

curun1r 10y ago
> If you were cracking a password wouldn't it be significantly faster to use GPU(s) rather than CPUs? When you're dealing with time scales greater than a decade, probably not. The right answer is almost always to wait until future hardware is available that can crack the password significantly faster than our current CPUs and GPUs. Whether that's quantum computers or just faster iterations of the kind of stuff we've got now doesn't really matter...the time spent waiting for new hardware is insignificant compared to the time spent waiting for calculations on current hardware to complete. But I agree that it's disingenuous to list numbers like that because they're meaningless and aren't at all the answer to the "How soon can my password be cracked?" question.
- web007 10y ago
  2^70 / 6,000,000 years / 365.25 days / 24 hours / 60 minutes / 60 seconds = 6.2 million reference guesses per second. Modern multi-GPU instances are 560,000x faster, 350 billion guesses per second. So that gets you to 6 million years / 560,000 = ~100 years. So "decade" isn't accurate in this case, but only because of the awful comparison to begin with. Comparing a 2013 CPU to even a 2013 GPU will give you a 100 or 1000x bump easily, and since this is a case of "embarrassingly parallel" operation your scale is much smaller than expected. Also note: 350 billion is for NTLM in 2012. I can't find equivalent stats for modern GPUs from a few minutes of searching on my phone, but I know they're a factor of 2-10x better, so 2^70 is easily within reach.
marcusfrex 10y ago
It's just for giving an idea about hardness. Of course GPU(s) or/and parallel processing far more better than that. We will put results with clusters and GPUs soon.

curun1r 10y ago

> If you were cracking a password wouldn't it be significantly faster to use GPU(s) rather than CPUs? When you're dealing with time scales greater than a decade, probably not. The right answer is almost always to wait until future hardware is available that can crack the password significantly faster than our current CPUs and GPUs. Whether that's quantum computers or just faster iterations of the kind of stuff we've got now doesn't really matter...the time spent waiting for new hardware is insignificant compared to the time spent waiting for calculations on current hardware to complete. But I agree that it's disingenuous to list numbers like that because they're meaningless and aren't at all the answer to the "How soon can my password be cracked?" question.

web007 10y ago
2^70 / 6,000,000 years / 365.25 days / 24 hours / 60 minutes / 60 seconds = 6.2 million reference guesses per second. Modern multi-GPU instances are 560,000x faster, 350 billion guesses per second. So that gets you to 6 million years / 560,000 = ~100 years. So "decade" isn't accurate in this case, but only because of the awful comparison to begin with. Comparing a 2013 CPU to even a 2013 GPU will give you a 100 or 1000x bump easily, and since this is a case of "embarrassingly parallel" operation your scale is much smaller than expected. Also note: 350 billion is for NTLM in 2012. I can't find equivalent stats for modern GPUs from a few minutes of searching on my phone, but I know they're a factor of 2-10x better, so 2^70 is easily within reach.

marcusfrex 10y ago

It's just for giving an idea about hardness. Of course GPU(s) or/and parallel processing far more better than that. We will put results with clusters and GPUs soon.