3 ms·
Because the SHA-generated value is available to any program which can employ all the cores of the CPU and all the cores of the GPU to try the generated password
by acqq 10y ago
Because the SHA-generated value is available to any program which can employ all the cores of the CPU and all the cores of the GPU to try the generated passwords in parallel, and one try is very, very cheap for SHA, compared to the "serious" algorithms, plus, anybody can buy special SHA breaking devices which are built all the time.
For example, this device, which was priced just 1300 USD tries
https://www.bitmaintech.com/productDetail.htm?pid=00020160912073506474G9tUPWlH069D https://www.bitmaintech.com/productDetail.htm?pid=0002016091...
11.85T hashes per second, that's 1 with 13 zeroes per second and that shows what today is possible to achieve so cheap. Elcomsoft's software for previous, non-weak algorithm, managed to try 150000 passwords per second using the GPU, that is, this weakening is like giving an attacker some tens of thousands of computers for free, or tens of millions of computers for $1000.
- camillomiller 10y agoGeez... Thanks
- ikeboy 10y agoAFAIK bitcoin miners can't be used to crack hashes. See https://security.stackexchange.com/questions/62800/is-it-possible-to-use-bitcoin-miners-to-decrypt-files-communication https://security.stackexchange.com/questions/62800/is-it-pos..., https://rya.nc/asic-cracking.html https://rya.nc/asic-cracking.html
- acqq 10y agoIf the hash is SHA256 they can, read your links.
- ikeboy 10y agoSorry, the second link has better info on exactly why it won't work directly.
- acqq 10y agoThanks. Yes, I agree completely, when it's "directly." The mining devices aren't designed specifically to crack the passwords, but the solutions have the raw processing power and use the same hash algorithm, it's just that somebody would have to adapt the chips for that given task, and for that he could keep most of what's already optimized, namely the fast SHA256 calculations in hardware. It won't be particularly hard to adapt some current solution, and the known speed benefit and power use would approximately remain.
- ikeboy 10y agoI think you'd need to design your own hardware, since the algorithm is hardcoded into these. And once you're doing that you'd lose the economy of scale that bitmain has.