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Is Bitcoin mining compromising the security of SHA256?

bitcoin.stackexchange.com

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Re: Is Bitcoin mining compromising the security of SHA256?

#11

Post by gibybo »

drakaal wrote: post #8
Tarang wrote: post #4

Earlier quoted context omitted.

The hashes that come out of bitcoin mining aren't just any ordinary hash you could use to crack passwords, though. The hashes have to begin with a number of 0s corresponding to the difficulty. Most password hashes (including the salt) hardly have these 0s so even as a lookup table the blockchain isn't very good.

You don't attack Sha with the miner, you generate prime factors. Those can then be used to attack any encryption. Not convinced this is what is being done. Just saying it doesn't matter about the salt for this to be worth while.

SHA has nothing to do with prime numbers. Bitcoin also has nothing to do with prime numbers.

Further, prime numbers are only useful in a very specific case of cryptography, nowhere near 'all encryption'.

Re: Is Bitcoin mining compromising the security of SHA256?

#12

Post by dnautics »

SwellJoe wrote: post #6

I believe this question exhibits a lack of understanding of what "mining" Bitcoins means. Or possibly how Bitcoin works. Or both. Mining Bitcoins is simply a search for an SHA256 hash matching a certain set of criteria. The mining hardware could theoretically be used to search for hash collisions faster than previously existing hardware, but that is of limited utility in the scenario of trying to find a specific hash…

What if someone is collecting everything, including the misses, from bitcoin mining and running some sort of statistical analysis on it to determine if there are patterns in the noise.

Re: Is Bitcoin mining compromising the security of SHA256?

#13

Post by gibybo »

dnautics wrote: post #12
SwellJoe wrote: post #6

I believe this question exhibits a lack of understanding of what "mining" Bitcoins means. Or possibly how Bitcoin works. Or both. Mining Bitcoins is simply a search for an SHA256 hash matching a certain set of criteria. The mining hardware could theoretically be used to search for hash collisions faster than previously existing hardware, but that is of limited utility in the scenario of trying to find a specific hash…

What if someone is collecting everything, including the misses, from bitcoin mining and running some sort of statistical analysis on it to determine if there are patterns in the noise.

Bitcoin mining generates 160 quadrillion bytes (160 Petabytes) of misses per second. The limit would be the amount of data that you could reasonably store and analyze, and we were at that limit long before Bitcoin came around.

(Although you can't actually collect the misses from other miners, because they never publish them).

Re: Is Bitcoin mining compromising the security of SHA256?

#14

Post by interstitial »

lucb1e wrote: post #9
pmiller2 wrote: post #5

Slightly. Bitcoin mining encourages people to build SHA256 crackers. It's not inconceivable that these things could be repurposed to attack other types of SHA256 attacks besides those relevant to the BTC block chain.

When "other SHA256 purposes" are implemented correctly, this is no issue at all. For example hashing passwords should use bcrypt or something similar, and HMACs should use long enough keys. While you may increase the search speed with ten orders of magnitude, it's still well beyond our current capabilities to successfully crack any SHA-2 hash. See also the answer I just posted on the SE question.

Since the hypothetical brokenness of SHA256 is unknown, can we be sure there is a "correct" way to implement "other purposes"? Surely, it's conceivable a new attack could exploit an unforeseen weakness in all those uses.

Re: Is Bitcoin mining compromising the security of SHA256?

#15

Post by dnautics »

gibybo wrote: post #13
dnautics wrote: post #12

Earlier quoted context omitted.

What if someone is collecting everything, including the misses, from bitcoin mining and running some sort of statistical analysis on it to determine if there are patterns in the noise.

Bitcoin mining generates 160 quadrillion bytes (160 Petabytes) of misses per second. The limit would be the amount of data that you could reasonably store and analyze, and we were at that limit long before Bitcoin came around. (Although you can't actually collect the misses from other miners, because they never publish them).

true. It is however, possible that some statistical analysis can be run on the hits, although interpretation would be convoluted since the initial value is SHA'd twice.

Re: Is Bitcoin mining compromising the security of SHA256?

#16

Post by interstitial »

I usually find stackexchange's discussions more than ample. There are many sites whose comment system and content could use a re-hashing by HN's nerdery, but stackexchange isn't one of them. (Unless we are playing the wayback game of re-posting a question from several years ago).

Re: Is Bitcoin mining compromising the security of SHA256?

#17

Post by jawr »

pmiller2 wrote: post #5

Slightly. Bitcoin mining encourages people to build SHA256 crackers. It's not inconceivable that these things could be repurposed to attack other types of SHA256 attacks besides those relevant to the BTC block chain.

I'm not sure it does encourage the use of SHA256 crackers.. It's about looking for/generating a particular hash, not cracking or breaking a hash; all that these miners do is generate more hashes quicker.

Re: Is Bitcoin mining compromising the security of SHA256?

#19

Post by quarterto »

adrianwaj wrote: post #18

Anyone had experience mining litecoin and bitcoin simultaneously? Does it make sense to do so on the same hardware?

Nothing you can build has any hope mining Bitcoin anymore. On the other hand, my pathetic GTX460 rig (~150kh/s) nets about 2LTC/month.

Re: Is Bitcoin mining compromising the security of SHA256?

#20

Post by adrianwaj »

quarterto wrote: post #19
adrianwaj wrote: post #18

Anyone had experience mining litecoin and bitcoin simultaneously? Does it make sense to do so on the same hardware?

Nothing you can build has any hope mining Bitcoin anymore. On the other hand, my pathetic GTX460 rig (~150kh/s) nets about 2LTC/month.

If it's lying around, would you want to do that? Litecoin is criticized for minimal infrastructure... ahh okay you are.. it's not hypothetical.

.. I've read extra memory really helps.

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