BitPenny.com: Sustainable Mining (NEW: Open-Source Client)

[OneFixt]

3/24/2013
BitPenny is switching to the Stratum protocol.
Please stop using BitPenny Client as it is not compatible with version 2 blocks and will no longer be supported or required.
Connection details will be published after upgrades are completed.

BitPenny Client is Now Open Source
Windows and Linux Binaries Available

BitPenny Client version 0.5.2 (2012-07-03)

• updated codebase to bitcoin 0.6.3
• fixed a bug in 0.5.1 which delayed reconnecting to the pool

First, a bit of bitcoin history.

A long, long time ago, when Slush's was the only pool in town and CPU miners battled GPUs for a piece of the proportional pie, BitPenny was born. BitPenny was different: it introduced the 0-volatility Pay-Per-Share model, instant payouts, and the most simple interface to date with only a bitcoin address required to start mining (no usernames, passwords, or registration required).  Being a pioneer in PPS - the only model where the pool risks losing its own bitcoins - BitPenny was soon forced to close due to excessive losses.  Yet, BitPenny had left its mark, and all of its innovative improvements have since been adopted, and adapted, by many pools in the bitcoin community.  

Sustainable Mining

Since the very beginning, pools have aggregated the power of thousands of individual miners, introducing centralized points of failure as well as the potential to perform chain-splitting and double-spending attacks against the bitcoin network.  BitPenny believes that it is time to pay attention to the health and security of the entire bitcoin network.  BitPenny is back.

• Cluster-friendly, allowing you to hook up an unlimited number of CPUs or GPUs.
• 0-latency work and full statistics from a sand-boxed client based on the official bitcoind.
• Strengthens the bitcoin network instead of being a central point of failure.
• Eliminates all wasted mining time with instantaneous fail-over to solo mode.
• Maintains the hashing power of the bitcoin network even in case of pool outage.
• Eliminates the 50% pool power problem - BitPenny cannot double-spend or create a fork.
• Low-variance Delayed PPS model immune to pool-hopping.
• Non-decaying shares let you disconnect without losing your work.
• Variance reduction using a pool credit buffer and transaction fees.
• As always, no registration required

Go to BitPenny.com to learn more and join the future of sustainable mining.

Join #bitpenny for help and to chat with fellow miners.

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[Silverpike]

OneFixt has been around since the first days of pool mining (search the forums if you want to see for yourself).  He is a pioneer in pooled mining, and I will vouch for BitPenny.  Bitpenny, until it was taken down by unscrupulous assholes, was the best pool service of it's day.

Welcome back Bitpenny!

[Sukrim]

What do you do when the pool has still ~500 BTC in outstanding shares but the block reward cuts in half?!

The system you're using is RSMPPS, as far as I see it (interestingly with custom share difficulty, probably to keep pool load lower).

What I find strange is the "shares never expire" part - this would mean it's intelligent to fetch a few shares if difficulty goes down and solve them later in the future if difficulty goes up. This also means you'll have to track every share in the pool forever...?!

Also:
"BitPenny can safely support over 50% of the network without the pool operator being able to execute double-spend attacks"
is not true, as no miner can choose which transactions get included in the block he's mining without having access to the source code. I really like the fact though that you're displaying all current transactions in the current block on a page (yes, it could be faked, but it's a great start!).

What's the 3% pool fee used for? Users host their own modified bitcoind-VM. I guess there's still an central element that collects the transactions + shares, but as there are other *PPS (not pure PPS) pools out there with lower fees, you'll need some very compelling reasons to use your system (and clog up some HDD space with a VM + complete blockchain I guess).

All the best with your pool anyways, it surely seems like an interesting concept.

[jojkaart]

"BitPenny can safely support over 50% of the network without the pool operator being able to execute double-spend attacks"
is not true, as no miner can choose which transactions get included in the block he's mining without having access to the source code. I really like the fact though that you're displaying all current transactions in the current block on a page (yes, it could be faked, but it's a great start!).

I presume that BitPenny works in a way inspired by the p2pool. In that case, it truly wouldn't be a problem if the pool had over 50% hashrate. However, only providing a binary version of bitpennyd reduces the credibility of this claim to ... well 0%.

[Luke-Jr]

each share is worth 97% of expected block reward (0.00020542 btc)

What? 97% of expected block reward is 48.5 BTC. I doubt you get that per share, unless the share difficulty matches network difficulty (in which case you might as well be solo mining). The algorithm on the next few lines explains a more standard PPS with 3% fee scheme, but that'd be 2567 Satoshis, not 20542... If BitPenny is really paying 0.00020542 BTC per share, it really does seem tempting, but it'll go broke very fast.

[Artefact2]

This is fubar in so many different ways, it's not even worth trying. Also, obligatory "binary magic software may steal my wallet".

[Stupidpal]

each share is worth 97% of expected block reward (0.00020542 btc)

What? 97% of expected block reward is 48.5 BTC. I doubt you get that per share, unless the share difficulty matches network difficulty (in which case you might as well be solo mining). The algorithm on the next few lines explains a more standard PPS with 3% fee scheme, but that'd be 2567 Satoshis, not 20542... If BitPenny is really paying 0.00020542 BTC per share, it really does seem tempting, but it'll go broke very fast.

This is what confused me as well. Maybe the shares take longer to submit or something?

[Sukrim]

each share is worth 97% of expected block reward (0.00020542 btc)

What? 97% of expected block reward is 48.5 BTC. I doubt you get that per share, unless the share difficulty matches network difficulty (in which case you might as well be solo mining). The algorithm on the next few lines explains a more standard PPS with 3% fee scheme, but that'd be 2567 Satoshis, not 20542... If BitPenny is really paying 0.00020542 BTC per share, it really does seem tempting, but it'll go broke very fast.

This is what confused me as well. Maybe the shares take longer to submit or something?

Did you even read the page? They clearly state that the use Difficulty 8 shares, not Difficulty 1 like most pools. On average you'll find a solution every 8 shares then

[OneFixt]

Sukrim, welcome and thanks for your comments!

What do you do when the pool has still ~500 BTC in outstanding shares but the block reward cuts in half?!

In this case, it would take more good luck for the backlog of outstanding shares to be fully paid.  Transaction fees would also help to pay for these older shares over time.

The system you're using is RSMPPS, as far as I see it (interestingly with custom share difficulty, probably to keep pool load lower).

The Delayed PPS model was developed independently, but does bear close resemblance to RSMPPS.  Since the way that the pool credit buffer is distributed may differ somewhat from what is implied by RSMPPS, I've chosen to use a different name and to explain the details.  The general idea, however, is the same.

What I find strange is the "shares never expire" part - this would mean it's intelligent to fetch a few shares if difficulty goes down and solve them later in the future if difficulty goes up. This also means you'll have to track every share in the pool forever...?!

While earned shares do not expire, getworks become stale normally and prevent this issue from arising.

Also:
"BitPenny can safely support over 50% of the network without the pool operator being able to execute double-spend attacks"
is not true, as no miner can choose which transactions get included in the block he's mining without having access to the source code. I really like the fact though that you're displaying all current transactions in the current block on a page (yes, it could be faked, but it's a great start!).

Each client submits winning blocks directly to the bitcoin network.  Blocks are verified against a local copy of the block chain using the standard ProcessBlock function, and any attempt by the server to double-spend or fork the chain would result in a block rejected by the client.

You can monitor the transactions locally as they come in by setting setprintblocks to true and observing the debug.log file:

Code:

bitpenny@BitPenny3:~$ ./c.sh setprintblocks true
bitpenny@BitPenny3:~$ tail -f .bitpenny/debug.log

The code will be opened up when BitPenny's hashing power gets big enough to be of concern, and miners will have the ability to implement finer controls at that point.

What's the 3% pool fee used for? Users host their own modified bitcoind-VM. I guess there's still an central element that collects the transactions + shares, but as there are other *PPS (not pure PPS) pools out there with lower fees, you'll need some very compelling reasons to use your system (and clog up some HDD space with a VM + complete blockchain I guess).

All the best with your pool anyways, it surely seems like an interesting concept.

The fees go towards paying for servers and bandwidth, development, and support.  Even though getworks are local, BitPenny uses a significant amount of bandwidth to push data to its nodes.  We also offer a perfect solution for CPU farms and similar users who may not be welcome in other pools due to high getwork/submission ratios.  BitPenny is an unusual pool in many ways, and the best way to see what sets it apart is to give it a try.

[OneFixt]

"BitPenny can safely support over 50% of the network without the pool operator being able to execute double-spend attacks"
is not true, as no miner can choose which transactions get included in the block he's mining without having access to the source code. I really like the fact though that you're displaying all current transactions in the current block on a page (yes, it could be faked, but it's a great start!).

I presume that BitPenny works in a way inspired by the p2pool. In that case, it truly wouldn't be a problem if the pool had over 50% hashrate. However, only providing a binary version of bitpennyd reduces the credibility of this claim to ... well 0%.

BitPenny was inspired by the bitcoind client, merging the accessibility, convenience, and network-supporting effects of local mining with the advantages of using a pool.  I understand your concerns about the binary; as stated on the BitPenny website, the bitpennyd source will be released after BitPenny has had a chance to grow and gain traction.

[OneFixt]

each share is worth 97% of expected block reward (0.00020542 btc)

What?

Thanks for pointing that out, the shares are based upon 97% of the expected value.  I changed the wording on the website to reflect this.

[OneFixt]

Also, obligatory "binary magic software may steal my wallet".

Sandboxed software cannot steal your wallet.

[Luke-Jr]

The system you're using is RSMPPS, as far as I see it (interestingly with custom share difficulty, probably to keep pool load lower).

The Delayed PPS model was developed independently, but does bear close resemblance to RSMPPS.  Since the way that the pool credit buffer is distributed may differ somewhat from what is implied by RSMPPS, I've chosen to use a different name and to explain the details.  The general idea, however, is the same.

Care to explain the difference? I don't see one.

[jojkaart]

BitPenny was inspired by the bitcoind client, merging the accessibility, convenience, and network-supporting effects of local mining with the advantages of using a pool.  I understand your concerns about the binary; as stated on the BitPenny website, the bitpennyd source will be released after BitPenny has had a chance to grow and gain traction.

I appreciate the goals. I just wonder if it really is a good idea to keep the source closed. Even to gain traction. Keeping it closed could easily cost you a lot of the traction you could get otherwise. For myself, as it is, I have no interest to move my miners to your pool. The fee combined with the closed source binary blop mean that your pool has nothing to offer me that I don't already get from Eligius (or Arsbitcoin).

- Joel

[OneFixt]

The system you're using is RSMPPS, as far as I see it (interestingly with custom share difficulty, probably to keep pool load lower).

The Delayed PPS model was developed independently, but does bear close resemblance to RSMPPS.  Since the way that the pool credit buffer is distributed may differ somewhat from what is implied by RSMPPS, I've chosen to use a different name and to explain the details.  The general idea, however, is the same.

Care to explain the difference? I don't see one.

BitPenny draws its fee from the poolcredit buffer while distributing the block rewards among outstanding shares (this is stated on the website).  BitPenny was designed before the RSMPPS definition was posted online, so it was not designed to fit under that definition.  The resemblance is coincidental.

[Luke-Jr]

After chatting with OneFixt about it, his system is actually more like a CPPSRB (Capped Pay Per Share with Recent Backpay), which is a super-simple and elegant exception to the CPPS*B model. The difference from RSMPPS is that RSMPPS will pay every share during the round some fraction proportionally if it hits no-more-funds (and make up the difference recent-later), whereas CPPSRB (BitPenny) will just discard (for payment later) the oldest shares for the current round in order to pay the more recent ones in full.

[twmz]

I have been pointing some miners to bitpenny for the last day or so and I can say it has been working well.  My effective hashrate (based on found shares) has been a bit more spikey with difficulty 8 work units, but that is to be expected.  My 24 hour averages are right where they should be and my % stales are as low as on any pool I've used (~0.3%).

The closed source binary isn't ideal, but doesn't bother me all that much.   I do hope that the daemon will be opened up at some point, but I wouldn't review it line by line even if it was, so it makes little difference to me, personally.  I have it installed on an isolated mining rig that has no wallet or other data to steal (not that I have any reason to believe it would try).

I hope others will find bitpenny appealing and the combined hash rate will increase to a sustainable level (15 GH/s is not enough, IMHO, given the current difficulty).  I also wish the fee was 1% instead of 3%, but I understand that until the pool grows large, it may not be possible to cover costs with only 1% fees.

I like the concept of pools like bitpenny and p2pool which allow people to pool their efforts without putting the network at risk by centralizing too much power over the blockchain.

[OneFixt]

I have been pointing some miners to bitpenny for the last day or so and I can say it has been working well.  My effective hashrate (based on found shares) has been a bit more spikey with difficulty 8 work units, but that is to be expected.  My 24 hour averages are right where they should be and my % stales are as low as on any pool I've used (~0.3%).

Thanks for the feedback.  The stale percentage can be lowered even further by lowering the getwork rate to 1 second (or less if supported by the miner).  The theoretical stale rate at 1 block per 10 minutes and 1 second per getwork is 1/600, or .16666%; we've been able to achieve a stale rate of .16725% over a period of 30 hours.

Code:

    "sessiongetworkcount" : 1997662,
    "sessionsharesfound" : 19132,
    "sessionsharespersec" : 0.21593608,
    "sessionstatsinterval" : 60000,
    "sessionsharessubmitted" : 19132,
    "sessionsharesverified" : 19100,
    "sessionsharesrejected" : 32,
    "sessioncredit" : 3.92352200,

The closed source binary isn't ideal, but doesn't bother me all that much.   I do hope that the daemon will be opened up at some point, but I wouldn't review it line by line even if it was, so it makes little difference to me, personally.  I have it installed on an isolated mining rig that has no wallet or other data to steal (not that I have any reason to believe it would try).

The source will absolutely be opened whenever BitPenny gains enough hashing power to pose a concern.  We are also considering opening it earlier, but will need time to carefully review and refine the code to reduce the possibility of attacks on the server.

I hope others will find bitpenny appealing and the combined hash rate will increase to a sustainable level (15 GH/s is not enough, IMHO, given the current difficulty).  I also wish the fee was 1% instead of 3%, but I understand that until the pool grows large, it may not be possible to cover costs with only 1% fees.

I like the concept of pools like bitpenny and p2pool which allow people to pool their efforts without putting the network at risk by centralizing too much power over the blockchain.

Thank you for being an early adopter!  We are actively seeking more miners and hope to see a more comfortable hash rate in the near future.

[OneFixt]

BitPenny Bonus
For the next 5 blocks solved by BitPenny, the miner who solves the block will receive 100 extra bitpennies.

[Luke-Jr]

100 extra bitpennies.

How about defining "bitpenny"? Logically speaking, I would assume it is 0.01 BTC, in which case you're offering 1 BTC?