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Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

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Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#31

Post by cleeus »

ComputerGuru wrote: post #25
cleeus wrote: post #24

As a dev you should take a look at the difference of hashes/s of the different algorithms. Some are measured in GH/s, some in MH/s, some only kH/s. E.g. MD5 is way faster then SHA256. So if you only use a strong hash for ensuring data integrity in the absence of adversaries and performance matters, you may prefer MD5 even in these days.

There's no good reason to use md5, period. If performance matters and security doesn't, use something like mmhash3. If security matters and speed doesn't, use something like SHA-512 (optionally truncated to 256 bits). If both matter, use something like siphash if a prf will do or blake2 if you need a true, high-speed cryptographic hash. (Actually, besides portability and interoperability, there's probably no good rea…

I have not looked deeply at mmhash3 (I guess it means murmurhash3), but wikipedia says:

[...] When using 128-bits, the x86 and x64 versions do not produce the same values [...]

which will make it unsuitable for cross-platform applications. I was talking about a usecase where you could also choose CRC32 from a security standpoint but want more collision resistance. How does blake2 performance compare to MD5?

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#32

Post by nitin_flanker »

Const-me wrote: post #28
mrb wrote: post #23

Earlier quoted context omitted.

2.14e14 is nothing. 8x 1080 Ti can crack that in less than 15 minutes (NTLM, MD4, MD5).

This page says 8x 1080 Ti can do 1.3e10 hashes/sec for NTLM: https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a27... To test 2.14e14 passwords, you need 4.5 hours. Add a single extra character to that password and the time will become too long regardless on your hardware.

Also, the OP didn't mention the use of symbols. Cracking even a 8 digit password that have symbols in it will become impractical to even consider.

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#34

Post by pmontra »

Roritharr wrote: post #30
vit05 wrote: post #29

Earlier quoted context omitted.

"At a current market value of about USD$0.22 per coin" wow

The regret I feel having given away all of my 100 bitcoins at that price point will forever haunt me.

Seconded. The bitcoin to USD ratio is like 1 to 2700 right now

http://www.xe.com/currencycharts/?from=XBT&to=USD

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#35

Post by mrb »

Const-me wrote: post #28
mrb wrote: post #23

Earlier quoted context omitted.

2.14e14 is nothing. 8x 1080 Ti can crack that in less than 15 minutes (NTLM, MD4, MD5).

This page says 8x 1080 Ti can do 1.3e10 hashes/sec for NTLM: https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a27... To test 2.14e14 passwords, you need 4.5 hours. Add a single extra character to that password and the time will become too long regardless on your hardware.

No it says 334.0 GH/s (3.3e11). But they actually do 441.4 GH/s (4.4e11) according to this HN submission using the latest hashcat.

I can understand why you were doubtful if you were off by 33x.

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#36

Post by aappleby »

cleeus wrote: post #31
ComputerGuru wrote: post #25

Earlier quoted context omitted.

There's no good reason to use md5, period. If performance matters and security doesn't, use something like mmhash3. If security matters and speed doesn't, use something like SHA-512 (optionally truncated to 256 bits). If both matter, use something like siphash if a prf will do or blake2 if you need a true, high-speed cryptographic hash. (Actually, besides portability and interoperability, there's probably no good rea…

I have not looked deeply at mmhash3 (I guess it means murmurhash3), but wikipedia says: [...] When using 128-bits, the x86 and x64 versions do not produce the same values [...] which will make it unsuitable for cross-platform applications. I was talking about a usecase where you could also choose CRC32 from a security standpoint but want more collision resistance. How does blake2 performance compare to MD5?

The wikipedia page might be a bit misleading - there's a 128-bit murmur3 that uses 32-bit math (works well on most every processor), and a 128-bit murmur3 that uses 64-bit math (much faster on 64-bit processors, much slower on 32-bit ones)

-Austin, Murmur author.

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#37

Post by Elv13 »

ihartley wrote: post #15
astrodust wrote: post #14

Earlier quoted context omitted.

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. https://en.wikipedia.org/wiki/Underwater_logging

The Hydro Quebec plants are near the arctic. Some of them are near the tundra line (where trees suddenly stop growing and lichen takes over).

Don't expect much rotting that far north. It will take centuries to even start to rot. Also don't expect underwater logging either. This is the Boreal forest, not the rockies one. It's even past the northern limit for Boreal Cedar, the only mildly valuable tree you might find. After that, you get young evergreen and pine. They burn before they get old and grow slowly due to the climate.

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#38

Post by jrimbault »

voycey wrote: post #12

Interesting 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)

Slightly tangential but:

7zip amazes me. It hasn't been regularly updated for years, and still comes out on top of most benchmarks. And yet I find that many, if not most, people on Windows use WinRAR.

It's good software, easy to install, easy to use, and it doesn't nag the user with warnings about licensing. I don't quite understand how WinRAR got popular in the first place with that kind of competition.

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#39

Post by 19eightyfour »

mrb wrote: post #18

In 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…

Am i correct in assuming that floating point operations would stress these machines even more so, so in other words if the hash computation somehow required lots of floating point calculations the time taken to crack would be much longer?

Re: Password Cracking with 8x Nvidia GTX 1080 Ti GPUs

#40

Post by jrimbault »

dragontamer wrote: post #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, so…

I think (not sure) that AMD is faster per $ not faster for mining specifically ? So it makes more sense when mining for bitcoin to buy the fastest per $ cards ?
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