Can this brute force a smart fridge?
Probably, but Jian Yang won't be happy.
Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
11–20 of 113 posts
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#12Interesting to see real world figures for bcrypt, also interesting that 7Zip's hashing algorithm seems extremely resilient (I assume it works on the same kind of difficulty / work factor that bcrypt uses but with a higher factor)
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#13Interesting to see real world figures for bcrypt, also interesting that 7Zip's hashing algorithm seems extremely resilient (I assume it works on the same kind of difficulty / work factor that bcrypt uses but with a higher factor)
had the same reaction... RAR similarly has good numbers.
Would love to see numbers for Argon2 :)
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#14Earlier quoted context omitted.
quebec hydro is a huge reason for the location of the OVH datacenter there. margins are thin in the massive bulk hosting/colo/dedicated server business. http://www.datacenterknowledge.com/archives/2013/01/17/ovhs-...
99% of the electricity in Quebec is from hydroelectric dams. This is how the costs are kept so low, and you don't really have to worry about resulting greenhouse gas emissions.
Semi-sorta. It did involve flooding huge amounts of Quebec, so there are consequences and greenhouse gas emissions due to rotting trees, but it's a different sort of equation.
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#15Earlier quoted context omitted.
99% of the electricity in Quebec is from hydroelectric dams. This is how the costs are kept so low, and you don't really have to worry about resulting greenhouse gas emissions.
Semi-sorta. It did involve flooding huge amounts of Quebec, so there are consequences and greenhouse gas emissions due to rotting trees, but it's a different sort of equation.
Depending on when the land was flooded, some areas may me good candidates for underwater logging now or in the future. Apparently in some places this is a great source of wood for high quality musical instruments because there aren't many old hardwood trees available anymore.
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#16> The GTX 1080 Ti is the go-to value card for deep learning at the moment.
Ah, that explains a lot. I recall seeing that AMD cards are being used for most of the Bitcoin / Etherium stuff right now, so I thought it was odd to see team-green used in this case. IIRC, AMD cards have faster integer performance, but are slower in floating-point than the NVidia cards. Password-cracking is primarily integer-based however, soooooooo...
But since they're actually building a Deep Learning Platform (and while waiting for other stuff... using it to quickly-test a password cracking solution), these benchmarks make sense. Plus, its an interesting datapoint in any case.
I do wonder what the AMD-cards would do however. Whether it'd be more efficient, or faster... (or hell: maybe conventional knowledge right now is wrong and NVidia is faster)
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#17bcrypt: 21kH/s scrypt: 750kH/s
The author didn't mention the work factor so I don't know how comparable the results are. But I thought the merit of scrypt over bcrypt was that it was memory hard, i.e. hard to run on a GPU. It doesn't seem to be the case.
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#18In 2010 I built an 8-GPU machine[1] (4 dual-GPU AMD HD5970) and wrote an MD5 bruteforcer (then faster than hashcat), doing 28.6 then 33.1 billion passwd hashes/sec with a software optimization:
http://blog.zorinaq.com/whitepixel-breaks-286-billion-passwo...
It's interesting to note that 6.5 years later a single GPU like the Nvidia 1080 Ti can match the whole 2010 machine (32 billion hashes/sec). This is a doubling of speed every ~2 years. Moore's Law is still alive and kicking (contrary to what many claim)!
[1] Incidentally posting this machine on HN is how I got pointed to Bitcoin thanks to the reply of a HN user :) https://news.ycombinator.com/item?id=2003888
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#19bcrypt: 21kH/s scrypt: 750kH/s The author didn't mention the work factor so I don't know how comparable the results are. But I thought the merit of scrypt over bcrypt was that it was memory hard, i.e. hard to run on a GPU. It doesn't seem to be the case.
The thing about bcrypt is that despite using small data structures in memory (kilobytes) it reads and writes and rewrites a lot of data into them (megabytes, when choosing common work factors). And the small size of its data structures is still just a bit too big to fit many parallel instances of bcrypt in GPU L2 caches. So it is effectively "memory hard" on GPUs.
Contrast this with scrypt which writes memory (typically megabytes) only once, and a byte is read, on average, only once.
bcrypt and scrypt are both, at the moment, memory hard on GPU, but for different reasons. bcrypt reads/writes many times a small buffer. scrypt reads/writes once a large buffer.
Don't pay too much importance on comparing the hash/sec of these 2 algorithms in this specific benchmark. The configurable work factors influence speed a lot.
One day L2 caches will be big enough and we will see a sudden massive cracking speed improvement for bcrypt. This isn't going to happen anytime soon for scrypt.
Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs
#20bcrypt: 21kH/s scrypt: 750kH/s The author didn't mention the work factor so I don't know how comparable the results are. But I thought the merit of scrypt over bcrypt was that it was memory hard, i.e. hard to run on a GPU. It doesn't seem to be the case.
The notion of scrypt being "memory hard" is from 2009. This is when GPU just started supporting 1GiB of RAM [1] 256MiB and 512MiB models were still common place. The 1080Ti supports 11x that [2] its a far cry to buy a GPU that doesn't support at least 4GiB.
Scrypt difficult is 128 bytes × N_cost×r_blockSizeFactor [3]. The "standard" parameters 16384 = N blocksize = 8 results in 16MiB of memory per instance.
On a 512MiB GPU that was only 32 instances in parallel. A modern 1080Ti (with 11GiB) that can be 704 instances. Now we're cooking with gas. Moore's Law it happens.
[1] http://www.anandtech.com/show/2744/2
[2] https://www.evga.com/products/productlist.aspx?type=0&family...
[3] https://stackoverflow.com/questions/11126315/what-are-optima...