[4+ EH] Slush Pool (slushpool.com); Overt AsicBoost; World First Mining Pool

[Psychoactive]

So I started mining on your pool today and right now according to my miner I have over 1500 accepted shares but in the "My account" page it is only showing around 300.

Can you help me understand a little better why that is?

Number of accepted shares in the "My Account" page is for the current block : 300 shares for the current block, and 1200 other shares on previous blocks, that are not displayed any more on this page.

[dishwara]

So I started mining on your pool today and right now according to my miner I have over 1500 accepted shares but in the "My account" page it is only showing around 300.

Can you help me understand a little better why that is?

That is nothing to worry. With your miner, you so far solved 1500 shares today only, for many blocks.  The my account page shows the shares in current block. 1500 = (300 share of current block + xxx shares of previous block + xxx share of previous block + ............)

[frankiebits]

Thanks , now I understand...

[xenon481]

It seems that the pool generated two instances of block 114114 according to the stats page, but one of them is a link to 114115 in block explorer.

Where do you see that??

Immediately after block is found, pool is asking bitcoind for last blocknum. But there is a bitcoind balancer, every request may go to another bitcoind instance (except submitting the block, where the instance must be the same for getwork and submit). This problem with blocknum happen when instance performing getblocknum() does not info about newly mined block yet.

P.S. To avoid confusing you, Thor, I corrected the blocknum manually .

Another instance of this where both Pool #2239 and #2240 report that they are for Network Block #114464, but #2240 is actually #114465.

Edit: The only reason I noticed was that I was curious about the percentage of blocks that we (the pool) are solving (today) compared to the rest of the entire network.

[frankiebits]

How come you switched to PPS? I had liked your older model, seemed like the payout was higher than PPS pools I tried...

[xenon481]

How come you switched to PPS? I had liked your older model, seemed like the payout was higher than PPS pools I tried...

This pool is not PPS and has never switched to PPS. It is Score Based.

[slush]

This pool is not PPS and has never switched to PPS. It is Score Based.

Correct. PPS is very vulnerable method and I don't plan to implement this. Everybody with few Ghash/s can bankrupt operator of PPS based pool in few weeks. I had few attacks to the pool already, so I don't want to open door for another one.

This pool is score based, which is the best known anti-cheating technique with fair payouts. The pool also keep the same rules as original Bitcoin mining (120 block confirmations, invalid blocks, stale shares), because I believe they are good enough. Also people who take mining seriously and don't need cash ASAP probably don't need PPS, because they cut their income for no reason (IMO, pls no flame).

But of course I like there are PPS based pools, because people have freedom of their choice and Bitcoin is about that.

[Ian Maxwell]

Hey slush, it would be really neat if in addition to the recent statistics and the hall of fame page, there were something like a "book of records" with things like

• longest and shortest rounds ever, or in the past week/month/whatever
• most and fewest shares contributed in a round
• highest Ghash/sec
• most users working at once

I found myself curious about some of these things the other day, and it would be cool if I had an easy way to look them up instead of bugging you about it every time.

[Grinder]

Correct. PPS is very vulnerable method and I don't plan to implement this. Everybody with few Ghash/s can bankrupt operator of PPS based pool in few weeks.

How?

[Meni Rosenfeld]

Correct. PPS is very vulnerable method and I don't plan to implement this. Everybody with few Ghash/s can bankrupt operator of PPS based pool in few weeks.

How?

I think slush is referring to the fact that with PPS, the variance for the operator is huge compared to the fees he collects. He can lose a lot of money with a few unlucky blocks, and with a high pool activity these can come very quickly. However, I don't think the problem is as great as slush describes. According to my calculations, and unless I'm missing something fundamental about the PPS model, the operator can make sure his probability of ever going bankrupt is less than u by keeping a reserve equivalent to ln(u)/(-2c) blocks, where c is the fee collected. For u=1/Million and c=0.1 this amounts to 3450 BTC.

[slush]

How?

• 1. Take poclbm
• 2. Modify it for checking shares against full difficulty. Don't send full difficulty shares to server. (1-2 lines changed)
• 3. Have a fun
• 4. Few weeks ago - pool closed

There are some modifications possible:

• a) Do this from your single IP. Careful pool admin probably ban you after >500k shares without found block.
• b) Install http proxy in your office/school, in your parents house, ask your friends to install proxy on their computers. You have probably next 10*500k shares to spend.
• c) Install Tor. Next milions of shares.
• d) There many other posibilities like free proxies, buying few zombies etc.

There is no defense against that. All risk is on the pool operator, on the single person. You can block IP ranges of Tor (but many people use Tor with pool already for their good reasons), you can implement blocking http proxies or whatever else. All those defense techniques are only "security by obscurity". With PPS you (as attacker) get paid for all shares except "winning" one, which is even worse than atack on score/share based, where by keeping winning shares you are also slightly cutting your income. This sabotage attack is well known, but with PPS it have yet another dimension of weakness.

[Meni Rosenfeld]

How?

Modify it for checking shares against full difficulty. Don't send full difficulty shares to server. (1-2 lines changed)

Oh. That. I am humbly reminded that not all problems can be solved by analyzing a stochastic process.

[frankiebits]

How come you switched to PPS? I had liked your older model, seemed like the payout was higher than PPS pools I tried...

This pool is not PPS and has never switched to PPS. It is Score Based.

Signed up for a bunch of pools and got confused by all the emails, sorry. It was a BTCMine (btcmine.com) email , here is what is said if your interested...

"Due most of miners want score or pps payout model, pool switched to score based payout model.
This model prevent possible loss for cpu miners and protect pool from timing attacks.
All already submitted shares calculated with 1.0 score and will be paid, when pool solve next block.
There is possible some small bugs due this update, please send your reports.

BTCMine Robot"

[[Tycho]]

There is no defense against that. All risk is on the pool operator, on the single person. You can block IP ranges of Tor (but many people use Tor with pool already for their good reasons), you can implement blocking http proxies or whatever else. All those defense techniques are only "security by obscurity". With PPS you (as attacker) get paid for all shares except "winning" one, which is even worse than atack on score/share based, where by keeping winning shares you are also slightly cutting your income. This sabotage attack is well known, but with PPS it have yet another dimension of weakness.

Well, there should be some really evil user that will be ready to sacrifice 10% of his multy-Gh/s income just for attacking some pool.

This attack is possible for any other pool, and it's even more evil because it will be against all the users of this pool, not the operator. Then users will realize that they are receiving some %% less and will switch pools.
In PPS pool good users will not be affected at all.

[slush]

Well, there should be some really evil user that will be ready to sacrifice 10% of his multy-Gh/s income just for attacking some pool.

Attacker does not loss anything, he can pull his >3 Ghash/s rig without _any_ loss for him.

In PPS pool good users will not be affected at all.

People will be affected by closing the pool. You're right, with share based pool the loss is divided between hundred or thousands of users. Which it also makes less attractive for the attacker, because then his motivation is only fun, not necessary closing the pool, because it's not so easy to do in this way (DoS is more likely).

Anyway I don't want to open discussion about this again. Sabotage attack is well known and described also in some PDFs (I cannot find the source right now, but there is discussion about that on this forum already). I just wanted to tell why I'm not providing PPS model.

[[Tycho]]

Well, there should be some really evil user that will be ready to sacrifice 10% of his multy-Gh/s income just for attacking some pool.

Attacker does not loss anything, he can pull his >3 Ghash/s rig without _any_ loss for him.

You forgot that there is 10% fee in PPS pools.

[dbitcoin]

I discussed yesterday with Tycho about PPS cheating problems, and completely forgot about this case
There is so much dumb asses,  who want a few "free and easy money".

p.s. every day some funny haKerZ spam my sever with longpolling request's at 30rq/s+ (as I predicted and send some messages about this to m0mchil).
      useless attempts anyway

[dacoinminster]

http://mining.bitcoin.cz/stats/?history=1000

I have changed my script to add an option to change the "Statistics" link so that it takes you to http://mining.bitcoin.cz/stats/?history=60 - this should show all the unconfirmed blocks for you guys without having to edit the URL as shown above.

I also added a link to an externally hosted chat room so that you guys can commiserate about high difficulty and those nasty extra-long blocks.

You can always get my latest UI enhancements script here: http://userscripts.org/scripts/review/98553

If this script is making your life easier, please consider a donation: 19hMEAaRMbEhfSkeU4GT8mgSuyR4t4M6TH

[bit4bit]

Please use the orange logo for favicon. Right now it's the same with this forum and it's confusing.

[bobR]

Lately is's crap... submit you shares we'll take them    guess what u got   squat
slush decays too rapidly
the last couple days are ...
but he clames it all averages out
Well I'm NOT seeing that
I'm seeing less pay out per day..pay out per share