Quote from: slush on February 04, 2011, 02:49:44 PM

No, it increase the variance a lot, which is against the purpose of pool.

Not that much and only for low-hash rate miners that have a lot of variance anyway because even now there are short rounds and for CPU-miners, there is not a matter of reducing variance but increasing probability of any payout and your pool will still work in this respect. The most variance in your pool comes from different level of "pool daily luck" anyway and this scheme will not change it.

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Also resetting on new block isn't solution, because bad guy can start mining on every new bitcoin block & stop after 43% of standard time between two bitcoin blocks. Maybe not such effective as cheating against current pool accounting, but this will still works.

No, it won't. The whole idea of the pool abuse is that you get paid in two places at the same time. With jgarzik's scheme, it's either or. Either you get paid from the pool, or individually. You never get paid twice. If you start mining on every bitcoin block and stop after some time, you either get paid from the pool (pool found a block) or from yourself (you found a block). Finding a block individually guarantees pool shares reset and all you accumulated shares loss. And finding a block by the pool guarantees that you did't find this block by yourself since the switch time.

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So I don't plan to change accounting itself.

It's your pool and your rules but I'd recommend you reconsider it because your strategy below is much more messy.

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I know that it is only matter of time, when somebody start to cheat pool with this technique. So I have prepared 'delayed' stats on the pool. With this update, nobody will known how many shares is in current block. This obfuscate real time statistics a lot, but remain completely fair for all miners and cheaters won't have enough data to know when to switch.

Actually, the only thing that the cheater needs is the time when the round started so he can join the pool. Since the I(lambda) function is positive, he can switch out anytime provided he joins when the round starts. You will not only need to hide the number of shares but the round starting time and the number of shares one accumulated in the given round (otherwise the cheater can connect one of its miners and see when the counter starts from zero). This way you can effectively turn off all the statistics and publish only "pool mining digest from yesterday". It will also be unfair to anybody who wants to join the pool (and not cheat) because joining midround is unfair. In my opinion, it will impact the usability of the pool much more than the jgarzik's counting method.

And although I'm not sure because I'm not fluent in the bitcoin protocol, I believe a bad guy can test the bitcoin protocol traffic to learn that it was the pool that found a block (and hence a new round started) by connecting to your 8333 port and getting your "new block found" broadcast before getting this message from other nodes. Even if you block your port and connect only to some trusted nodes, by listening to other nodes traffic, he may estimate the probability that you found the block and not a guy in, say, Japan which will have a different node propagation signature. He does not need to be right 100% of the time, being right more than not will be enough. Remember, joining and switching off from the pool at complete random intervals is payoff neutral (apart from startup inefficiencies) so it will be enough to join more frequently at the start of the round than not. And by looking at the delayed statistics he can check if the strategy worked.