You'd better check smoothie's past posts before calling him running mate, some of those are quite abusive.

If you claim to be neutral you also need to be able to stand to your principles.

Weekly Update #11

• Proof-of-work difficulty stabilized over 16000 this week.
• Proof-of-stake blocks account for more than half of the blocks in the past several days. It is expected in the next month or two proof-of-stake blocks would reach the 10 minute spacing target and proof-of-stake difficulty should begin rising above the current minimum of 1.

Have fun and next week!

Weekly Update #10

• Proof-of-work difficulty temporarily peaked at 15732 at block #11509 this week following some buying strength on the Bitparking exchange.
• There was some effort to figure out the memory leak encountered with mining pools. So far it appears to be an elusive bug.

Not much else to report on this week. So have fun and see ya all next week!

Yes leave client running would automatically generate stakes. Keep it running is better but you don't have to keep it running all the time.


Current checkpoint policy tries to checkpoint every proof-of-work block and up to the 6th consecutive proof-of-stake blocks or max 4-hour old block. When proof-of-stake blocks become more frequent there is some room for reorganization.

This sounds like a rather warped view of monetary history pretending that people/market had a choice to still use gold as medium of exchange.

It's understandable though as you'd probably need to reject store-of-value in order to have faith in demurrage.

http://www.wired.com/threatlevel/2009/06/e-gold/

http://online.wsj.com/article/SB10001424052748704425804576220383673608952.html

https://bitcointalk.org/index.php?topic=55242.0

Dunno I feel there is quite a bit noise in the valgrind report. After generating ~100 blocks on my testnet node I got 3KB definitely lost, 6KB indirectly lost and 1KB possibly lost. And the stacks don't look plausible at causing GB range leak problems. It would most definitely help to have a reproducible setup where large amount of memory is known to have leaked.

I tried valgrind on a testnet node with cgminer, but so far no luck finding useful clues.

Based on what I have heard so far, it seems this is related to getwork. Since a pool at most generate ~100 blocks a day, coinotron said he had to restart ppcoind once a day, I assume that ppcoind was eating >1gb a day, so this excludes the possibility the leak is related to valid blocks (each block taking about 10KB~100KB).

Now getwork does maintain a list of block candidates and a leak there could account for the rapid memory increase. I didn't change things related to allocation and delete of these block candidates and a code review there didn't reveal obvious problem either. I believe cs_main is also used to serialize getwork access so there shouldn't be concurrency issues with the block candidates.

Andy I seem to remember you were testing with some pool software earlier and also observed memory leak issue. Is there a simple way for me to set up a pool software and reproduce this situation? Can you all (Chris, coinotron, Andy) confirm my observations? How fast is ppcoind leaking memory in your production system? Is the leak speed roughly proportional to the number of getwork requests?

Thanks,

I don't think 1% annual interest is a valid trigger of deflationary spiral. Deflationary spiral is a debt problem as far as I understand.

Although it is possible that most users stop generating stakes and the network loses security. It's a possibility but of course the same can be said for bitcoin as well. If it does materialize that the incentive structure is not adequate to maintain reasonable security then improvements would be considered. For example, there is already a discussion on-going regarding the possibility of allowing minters to offline spend keys and reduce risk.


Since we did not try to address the initial minting problem so proof-of-work is still needed, and we feel it's kind of arbitrary to fix a schedule to stop proof-of-work minting, so ppcoin remains a hybrid design and no preplanned phaseout of proof-of-work is built in. Also as a real cryptocurrency you have to consider from market's point of view if miners are all excluded from the ppcoin market after a short time period then adoption is likely very limited. That's why a relatively slow declining mint curve is chosen to match bitcoin's.

Even if ppcoin itself doesn't become fully energy efficient, we feel that the design already demonstrates how it can be achieved for future cryptocurrencies.

ppc = peer-to-peer coin

Hi Volksholk,

  Yeah I can confirm what dreamwatcher said. I'll see if I can add some quick fix in the next release (no plan on full support of gui still). But mostly looking forward to dreamwatcher's improved gui with explorer functionality.

 

Yeah that's what I plan to do first to see if I find anything. Thanks,

I'll see what I can do regarding the memory leak, but as I don't have a reproducible setup some help is likely needed from the pool operators who are running into the issue.

Hi freequant,
  Thanks for the comments. See below answers:

• There is a transaction fee, only that fee is not paid to miners/minters, but is destroyed. We simplified transaction fee calculation and set a minimum 1 cent per KB fee. To further reduce dust spam we also enforce that minimum payment amount is 1 cent as well.
• Stake is withheld to maturity (520 blocks) so you cannot spend them until they mature. Once matured it returns to balance and then you can spend them. One item on my todo list is to automatically select coins with less coin age on them when spending, to reduce coin age loss of the user.
• Yes the proof-of-work mint curve is also heavily affected by market participation. If market participation stays constant then Moore's Law will ensure mint reduction. Even if Moore's Law discontinues and difficulty stops increasing (after many years), mint quantity would stay constant but inflation rate may not be that high. For example if you reach 100M money supply and 2M constant annual production, annual inflation is only 2%. Some alt-coins are already running with constant generation because over really-long term inflation is still approaching zero. But ppcoin should approach low inflation much faster than those, comparable to bitcoin's reduction schedule I think.

ASIC should be able to mine ppc I don't see why not. Although I am waiting for an actual confirmation from someone with ASIC (dunno if there is anything shipping now) to be 100% sure. I don't yet have a confirmation on whether one of fpga miners works. Although nobody complained about not working either.

As to 51% attack, having >50% mining power of the network is not sufficient to control main chain once the proof-of-stake protection is stable. Right now central checkpoints protect the blockchain as well.

Week Update #9

• ppcoin has passed block #10000 this week at 10:41:39 UTC on October 15, 2012
• Proof-of-stake difficulty has dropped to 1. Last couple of days the frequency of proof-of-stake blocks has reduced compared to last two weeks. This is because 30 days ago the proof-of-stake blocks just started appearing so most coins eligible have already participated in block generation, causing a lack of eligible coins currently. The average size of stake generating blocks are expected to become smaller in the next couple months and proof-of-stake frequency will become more stable and start pushing up difficulty from it's minimum at 1.
• Due to my heavy schedule around the end of the year, work on the client is slowed down. There will be a delay for the next release.
• There was some complaints that bitcoin 0.7 rollout wasn't smooth. I don't know the details so if there is something to take note, welcome to message me about this topic. I would probably wait a while before reviewing bitcoin 0.7 and planning for a merge.

Have fun and next week!

This is exactly what ppcoin project is trying to achieve, to demonstrate that work is not required to secure block chain, thus further reducing the cost burden on users of future cryptocurrencies.

J. Becker et al in a lengthy and possibly prejudiced paper 'Can We Afford Integrity by Proof-of-Work?' argued that Bitcoin is not affordable compared to existing infrastructure. I don't necessarily agree with that as Bitcoin may be affordable enough but high energy consumption is one of the very few legitimate criticisms on Bitcoin in my opinion.

The inflation model of ppcoin is designed to be comparable to Bitcoin's, although without the hard limit of Bitcoin's 21M (the 2 billion max value is only a safety limit and may not be approached).

I estimate 2012 ppcoin production to be around 15 million (less than half year), 2013 ppcoin production to be around 10-20 million as well. Annual ppcoin production should be less and less based on Moore's Law.

See our FAQ section on 'Is there a cap on total money supply like Bitcoin's 21 million?' for more detailed explanation: https://github.com/ppcoin/ppcoin/wiki/FAQ

I have stated this numerous times, the goal of ppcoin project is to demonstrate energy consumption is not required to secure a cryptocurrency. If you want an implementation of your hybrid proof-of-stake design you are free to start your own coin, forking off ppcoin code is also welcome. I would only consider enhancement proposals that preserve energy-efficiency of ppcoin.

It may be doable to persist and broadcast evidence of duplicate stakes and punish the offending address in some way (rejecting stake from this address or even outright reject spending). Although this would require much more careful design to avoid introducing other problems.