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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

#41

Post by a_t48 »

jrimbault wrote: post #38
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.

I've never had file associations working with 7z on any machine. :/

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

#42

Post by lightedman »

nitin_flanker wrote: post #32
Const-me wrote: post #28

Earlier quoted context omitted.

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.

Process of elimination restricts character and symbol sets, generally, narrowing your set of possible combinations greatly.

The best way to crack a password isn't to brute-force it first, it's to first analyze who made the password, and the password system, to narrow down all possibilities before you try brute-forcing.

Example; if a person is American, you can pretty much assume they're restricted to the typical US keyboard and its symbols, for 90+% of the population. Very few people know of ALT codes or unicode or even the character map, even in IT. That narrows your symbol subset down dramatically. System for passwords truncates after 12 characters, has a minimum of 8? You already know you don't need to try doing anything with more than 12 characters, and you can limit your password cracking to starting with 8 characters and ignore anything with fewer than that. That eliminates a whole slew of brute-forcing that is required, as you've now narrowed down the password range.

All it takes is a little thinking. Man can make it, man can break it, there is simply no exception.

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

#43

Post by lightedman »

jrimbault wrote: post #38
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.

7zip seems to love to lose file association or simply fails when I double-click a .rar or .7z file, saying file type not recognized (nevermind the fact I just made that very archive with 7Zip!)

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

#44

Post by lightedman »

jrimbault wrote: post #40
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 ?

Originally ATi (right in the middle of being acquired by AMD) was killing nVidia in the bitcoin mining arena. People were buying 5770s left and right for the crazy hashrate they were getting.

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

#45

Post by PeterisP »

jjordan wrote: post #3
walrus01 wrote: post #2

as with most really high electrical loads, if you can operate it remotely, do so. There's places in North America near major hydroelectric dams with electricity that costs $0.03 to $0.045 per kWh. Running something like this and the cooling needed for a 3kW thermal load on California electrical prices is a good way to burn money.

Someone password cracking with 8 GTX 1080's isn't likely worried about the electricity costs associated with said cracking.

If you anticipate a full load and include cooling, already within a single year the electricity costs more than the GPU hardware - so yes, even (and especially!) if you're buying top end gear then electricity costs matter, it's more expensive than the shiny stuff.

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

#46

Post by m1el »

19eightyfour wrote: post #39
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?

There aren't any widely used hashes that require floating point computations. Other than that, floating point instructions are usually slower.

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

#47

Post by algorias »

lightedman wrote: post #42
nitin_flanker wrote: post #32

Earlier quoted context omitted.

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.

Process of elimination restricts character and symbol sets, generally, narrowing your set of possible combinations greatly. The best way to crack a password isn't to brute-force it first, it's to first analyze who made the password, and the password system, to narrow down all possibilities before you try brute-forcing. Example; if a person is American, you can pretty much assume they're restricted to the typical US k…

I believe the poster upthread already considered only restricted characters (upper + lower + digits), so the difficulty they stated is what remains after your analysis.

> Man can make it, man can break it, there is simply no exception.

Nice platitude, but this is simply not true.

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

#48

Post by ASlave2Gravity »

pmontra wrote: post #34
Roritharr wrote: post #30

Earlier quoted context omitted.

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

What's caused the price to rise so much the past few months?

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

#49

Post by bastijn »

ASlave2Gravity wrote: post #48
pmontra wrote: post #34

Earlier quoted context omitted.

Seconded. The bitcoin to USD ratio is like 1 to 2700 right now http://www.xe.com/currencycharts/?from=XBT&to=USD

What's caused the price to rise so much the past few months?

Accepting by major parties and even speculated governments (Japan I believe) was one. In generic, being able to spend it in more places as well as people seeing the potential of trading in it.

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

#50

Post by nikcub »

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.

You can get over that feeling very quickly by reminding yourself to focus on what you might be missing out on today that you don't want to regret in years from now.
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