Bounty for the confirmation that stratum modification works

[crazy.bustard]

Hello.

Recently I found the modification of the stratum on github ( https://github.com/bad-motherfucker/stratum-mining-proxy ).

This modification actually should not sending solution for solving the block. This modification could be used for sabotaging the mining pools by reducing their luck. I know that the peoples from ghash probably used this type of modification to reduce luck in other pools.

I would like to give the 2.5 BTC for the person who will be first to provr that this modification will work/not work.

Regards CB

[MWNinja]

Here's the relevant bit of code, I've commented it to make it understandable

# if we found a solution that is less than the current difficulty
 if ntarget >= utils.uint256_from_str(hash_bin):

            # write the log that we found a block
            log.info('Found block: %x' % utils.uint256_from_str(hash_bin))
     
            # now we do something nefarious, but not universally as that would make it easy for the pools detect
            # randomly based on a probability argument (set on command line) withold the solution
            if random.random() < self.witholding_probability:
                log.warning('Witholding this block (p = %f)' % self.witholding_probability)
                return False


The cool tricky part is the attacker can just claim bad luck, as they aren't withholding all the blocks they find, but just a percentage.   

[-ck]

And if you're not on a PPS pool trying to sabotage it, what is the reason one would want to do this? Yes it does withhold blocks, but virtually every pool does not use pps and you stand to lose btc by performing it on them.

[MWNinja]

And if you're not on a PPS pool trying to sabotage it, what is the reason one would want to do this? Yes it does withhold blocks, but virtually every pool does not use pps and you stand to lose btc by performing it on them.

You still get paid when someone else in the pool finds a block, basically you are sabotaging the pool for your benefit only.  The reward is certainly lower and it hurts everyone mining in that pool; but the side effect is that your hashrate will NOT increase the difficulty as it's not contributing to the actual block discovery rate.  A party with a large hashrate can thus over time potentially realize more income by stealing from pools using this method, as the hashes he is contributing don't increase difficulty. 

Possible Solution
When a pool finds a block, transmit the successful nonce to other miners in the pool.  The miners that don't respond with a valid block are cheating you...and thus their account should be locked from future payouts.

[-ck]

Work out the numbers... you'll see you lose out by doing it except on a pps pool, and virtually all pools have abandoned this dangerous option.

[megahash]

virtually all pools have abandoned this dangerous option.

BAN changed over to PPS, and there have been a constant stream of complaints from miners there (me included) about not getting paid the correct amount - possible connection? If PPS is so dangerous, why would a pool change over to it?

[-ck]

virtually all pools have abandoned this dangerous option.

BAN changed over to PPS, and there have been a constant stream of complaints from miners there (me included) about not getting paid the correct amount - possible connection? If PPS is so dangerous, why would a pool change over to it?

There's no doubt that it's a drawcard to miners because of the lack of variance in pps mining, making it a good way to attract miners. But history has shown that it is unsustainable in the long run no matter how large a pool is (even f2pool aka discus fish will eventually drop it I'm sure). It's a lot like the "doubling" odds people take on coin toss, red/black roulette odds etc - the fact is that eventually there will come a time that the odds will be so bad for you that you lose. Even if you were the entire bitcoin network, it might be impossible to safely run PPS indefinitely. OOC did an analysis of it a while ago if I recall correctly saying how much the pool operator had to have in reserve to run PPS and the associated fees required to make it sustainable according to risk. Pools that ran SMPPS thinking it was safer basically realised it was not and abandoned that in favour of a less risky payment system. I can't find the PPS link right now but here's the smpps discussion:
http://organofcorti.blogspot.com.au/2012/04/32-risks-of-smpps.html

[megahash]

virtually all pools have abandoned this dangerous option.

BAN changed over to PPS, and there have been a constant stream of complaints from miners there (me included) about not getting paid the correct amount - possible connection? If PPS is so dangerous, why would a pool change over to it?

There's no doubt that it's a drawcard to miners because of the lack of variance in pps mining, making it a good way to attract miners. But history has shown that it is unsustainable in the long run no matter how large a pool is (even f2pool aka discus fish will eventually drop it I'm sure). It's a lot like the "doubling" odds people take on coin toss, red/black roulette odds etc - the fact is that eventually there will come a time that the odds will be so bad for you that you lose. Even if you were the entire bitcoin network, it might be impossible to safely run PPS indefinitely. OOC did an analysis of it a while ago if I recall correctly saying how much the pool operator had to have in reserve to run PPS and the associated fees required to make it sustainable according to risk. Pools that ran SMPPS thinking it was safer basically realised it was not and abandoned that in favour of a less risky payment system. I can't find the PPS link right now but here's the smpps discussion:
http://organofcorti.blogspot.com.au/2012/04/32-risks-of-smpps.html

Interesting, thanks. Is there any way to find out if a pool is using a modified stratum implementation, apart from asking the pool dev? I'd ask BAN myself, but they seem unable to answer even a basic question.......

[-ck]

Interesting, thanks. Is there any way to find out if a pool is using a modified stratum implementation, apart from asking the pool dev? I'd ask BAN myself, but they seem unable to answer even a basic question.......

All you can do is ask.

I think the bulk of the pools out there run variations of the major pool software available but no doubt a few run their own custom software. I've currently been working on my own pool implementation in c to try and redefine how a pool should perform and have posted a solo mining pool solution as a development prerelease and there will be a comprehensive regular pooled mining solution presented shortly, but my code is all open free software so I expect new (and some old) pools may come to start using it in the near future as they hit limits with existing software solutions.

[s0br]

virtually all pools have abandoned this dangerous option.

BAN changed over to PPS, and there have been a constant stream of complaints from miners there (me included) about not getting paid the correct amount - possible connection? If PPS is so dangerous, why would a pool change over to it?

Ckolivas...

PPS is can only be dangerous to someone who can not float a balance to pay miners during bad luck rounds. If you flip a coin 10,000 times it's going to be very close to 50/50. If a pool is simply banking on making some small fee for PPS...I'd understand... I think it's irresponsible to tell users this as I think it's the ONLY payment system that makes any sense. No miner should ever be put in any position where they have to 'trust' the statistics provided by any pool... This accounting for BTC mining expectations need to be in the hands of the miner, not the pool. There has to be a checks and balances system in place. I'm currently working on finding a tech auditing firm that can guarantee the pool is doing everything within its technical abilities to be 100% accurate with share and payment reporting.

We pay as frequent as hourly after the first 10 minutes of mining in our pool... there's virtually no risk to any miner


Megahash...I'm online answering questions all the time... The entire payment backend was coded from scratch. There's a 12.5% bonus payout not just as a promotional thing but an idea to give us a good cushion in case of any bugs, etc. I know I've been working around the clock the stabilize and make everything as accurate as possible. There's not one single user than can claim they ever made less than 100% of estimated earnings based on their hash rates. We have nodes all over the world to keep invalid shares/rejects to an absolute minimum and still have more coming online soon.

You were one of the winners of mining hardware we gave away... you have tracking information.. I know your account is comfortably over the 100% expectancy....

We're the biggest miners in the pool... we have a new 25k sq ft datacenter opening this week and will always be able to pay PPS.

[-ck]

If a pool is simply banking on making some small fee for PPS...I'd understand... I think it's irresponsible to tell users this as I think it's the ONLY payment system that makes any sense.

My comments are irresponsible? Heh, we'll see.

[s0br]

If a pool is simply banking on making some small fee for PPS...I'd understand... I think it's irresponsible to tell users this as I think it's the ONLY payment system that makes any sense.

My comments are irresponsible? Heh, we'll see.

Indeed! Don't take it personally.. wasn't meant to be an attack.. I'm offering a suggestion... I realize most miners don't have the ability to run a pool and they have to accept what I consider to be an extremely limited selection of pools. I've been bugging you to consult for us... you know I love your site, your intelligence, attention to detail... I need 3rd parties that would have access to running code to offer additional elements of transparency to the mining community. I think people need to expect certain level of accounting standards (despite anyone's belief of risk)... Most of us spend an unbelievable amount of money, regardless of amount it's all important... Ill get back to work..

[IYFTech]

Sorry s0br, but have you read your own pool thread lately/at all?

It is full of complaints from miners not being paid for what they have mined and has been since day one, as well as a myriad of other things. From what I can make out after reading it, for every miner that tries to complain, there are 2 or 3 shill accounts that attack & ridicule them. I myself signed up when your pool first started, as you know, but had to leave due to the issues with it. I later came back to see if things had improved, but the whole thread had degenerated into an embarrassing joke.

And you call ckolivas irresponsible? That's a little rich I think.