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Other => Off-topic => Topic started by: Xenland on August 02, 2011, 02:06:21 PM



Title: Using hash power to crack aes256 file?
Post by: Xenland on August 02, 2011, 02:06:21 PM
Most notable with the insurance.aes256 file. Is there a simple way to point my miner to cracking this file? I'm anxious to know whats in it...


Title: Re: Using hash power to crack aes256 file?
Post by: SgtSpike on August 02, 2011, 03:24:54 PM
I think cracking AES256 is about as difficult as cracking SHA256, which means you're gonna have to point your miner for the next several billion years before you get any results.

Good luck.  ;)


Title: Re: Using hash power to crack aes256 file?
Post by: Xenland on August 02, 2011, 03:34:03 PM
The plus side is that you only need a password to unencrypt. I think sha256 is hashing although they are the same algorithm lengths(256).
So basically my idea is to do a bruteforce instead of literally cracking it.


Title: Re: Using hash power to crack aes256 file?
Post by: SgtSpike on August 02, 2011, 03:37:55 PM
The plus side is that you only need a password to unencrypt. I think sha256 is hashing although they are the same algorithm lengths(256).
So basically my idea is to do a bruteforce instead of literally cracking it.
Oh, yeah, that's a good point.

Well, what you want to look for is an OpenCL AES cracker.  Not sure if one exists, but maybe try some googling?  Or maybe someone here has an idea...


Title: Re: Using hash power to crack aes256 file?
Post by: BCEmporium on August 02, 2011, 08:40:54 PM
So, trying to peek the wikileaks insurance file, are we? I doubt Assange leave a nearly possible to brutte-force password... even with all the computing power present at bitcoin network.


Title: Re: Using hash power to crack aes256 file?
Post by: qbg on August 02, 2011, 10:32:42 PM
Most notable with the insurance.aes256 file. Is there a simple way to point my miner to cracking this file? I'm anxious to know whats in it...
AES and (double) SHA256 are very different things (AES is encryption, SHA is hashing), so your miner isn't going to be useful at all. Remember that the miner doesn't even crack SHA256.

It seems likely that even quantum computers won't help you with AES (other than turning 256 bit AES effectively into 128 bit AES), so your only real option is to become very good at math and find a weakness in AES.


Title: Re: Using hash power to crack aes256 file?
Post by: Xenland on August 03, 2011, 02:45:00 AM
Interesting answers, does anyone know how long it would take to bruteforce starting at a high number then going in reverse? Like lets say i start at a 256 length password with all capital Z's?

Furthermore now that i think about it how do you brute force a password with out ascii characters?


Title: Re: Using hash power to crack aes256 file?
Post by: BCEmporium on August 03, 2011, 12:50:26 PM
Brutteforcing doesn't rely on hashing speed, yet in the time a computer would take to try to decrypt until output an error and try again.
This means you probably would be long dead, along with your grandsons, prior to get that thing open.


Title: Re: Using hash power to crack aes256 file?
Post by: JoelKatz on August 03, 2011, 01:15:28 PM
If you could try a billlion, billion keys per second, for a billion centuries, you could test one three hundred thousand billion, billion, billion, billionth of the possible keys. On the bright side, on average you only have to try half of them.


Title: Re: Using hash power to crack aes256 file?
Post by: compro01 on August 03, 2011, 03:03:43 PM
you do not get scale.

assuming the network could do AES encryptions as fast as it can do SHA256 hashes and you turned everyone towards cracking the AES encryption via brute force:

2^255/15.5 trillion per second=1.21*10^56 years


Title: Re: Using hash power to crack aes256 file?
Post by: Xenland on August 03, 2011, 04:53:44 PM
What if someone wrote a program that had a centralized network that would distribute passwords ranges to bruteforce? How long would that take I wonder with the current number of bitcoins users.


Title: Re: Using hash power to crack aes256 file?
Post by: compro01 on August 03, 2011, 06:01:39 PM
What if someone wrote a program that had a centralized network that would distribute passwords ranges to bruteforce? How long would that take I wonder with the current number of bitcoins users.

assuming the same as above (15 trillion encryptions per second) and a 20 character (truecrypt's recommended minimum length) password selected from ASCII printable characters (a-z, A-Z, 0-9, and all symbols), it would take

(94^20/15.5 trillion)/2=2.97*10^18 years

or shortly after the entirety of this galaxy is either thrown from it or engulfed by the huge black hole in the middle.


Title: Re: Using hash power to crack aes256 file?
Post by: BCEmporium on August 03, 2011, 06:13:21 PM
Xenland:

Useless attempt.
You would have to split it in two "worker chains", chain A generation pwds, chain B testing generated pwds. As you would never get the 15 trillion pwds/sec compro1 is speaking, taken the 2GB size of that file you would get instead like 2 or 3 attempts per minute by each worker on chain B.
Figure what that means...


Title: Re: Using hash power to crack aes256 file?
Post by: JoelKatz on August 03, 2011, 10:16:20 PM
The problem is that this is a "front door" attack, attempting to do exactly the one thing the algorithm was specifically designed to make impractical.


Title: Re: Using hash power to crack aes256 file?
Post by: BCEmporium on August 03, 2011, 10:30:33 PM
The problem is that this is a "front door" attack, attempting to do exactly the one thing the algorithm was specifically designed to make impractical.

The only backdoor attack is to reverse the algorithm and make it spit the key... I heard there's a nobel prize on math for the one doing it.  ;D


Title: Re: Using hash power to crack aes256 file?
Post by: Xenland on August 03, 2011, 10:41:59 PM
Well that clears that up, thanks everyone for helping me save a whole lifetime of trouble :P