Welcome back.

I say miracle too. :-)

Wow, that's amazing. Clearly one is causing the other, but which!?

All you need to spend your coins is your private keys which are in your wallet.dat file. One copy will work as well as another.

You don't really download the coins. It's more like you download a list of which addresses contain coins and the your software notices "Hey, that's an address I have the key for" and tells you the total balance of all such addresses.

That's right. If you received 5 cents in transaction previously then you have 5 cents in one address and it will get split. If you previously received a 1 cents transaction as part of your 5 cents then you will just send that and not any change.



You could make payment in two separate transactions, but why? The software handles it all. You just tell where to pay and how much and it's all taken care of.

I would leave off and memorize at least a few digits. When the cops capture you they are going to photograph your naked body.

Okay, true enough. I should retract 'variability'. But if a block clears out all or most fee paying transactions then there will be a period of waiting for transactions with fees to pile up to make it worth electricity even. During this period it might be worth it to work on the old block that did have lots of fees in it.

Right. So we've got a spender who wants to get in a block then once that happens we've got a miner who wants his block built on (the receiver has a similar desire, but doesn't care which version it gets in, just that it gets built on asap). Right now other miners choose to do this based on whichever version they hear of first, but I know if this is actually a lasting equilibrium. It does seem to be a local equilibrium since everyone knows that everyone else is just going with the first that they see it makes no sense to keep trying to find another version, but this can be broken if there is a way to pay the miner who builds on you .01BTC. This is rational to offer because of the chance of a race. Suppose something like a 1% chance of racing and consider that you only pay if you get included and it makes sense to offer a lot more than .01 if you need to. Right now this doesn't change much, but when there is high variability in the block reward because it is dominated by fees, some miners will rationally choose to continue working on a previous block as long as it has higher fees than the 'correct' block to work on. This will largely not actually happen because the finder of the previous block will know to pass on some of his fees to anyone who builds on him to tip the balance toward working on the next block instead of competing with his version of the old block.



 

Really? What exactly is the incentive for taking those extra risks if not some advantage?

We actually shouldn't be worried about our sends falling out of the chain, they can be put back, and we can't be defrauded by that. It's the ones we receive that we want buried quickly.

 

Strictly speaking I could buy thousands of GPUs to bury transactions coming to me faster making it harder for an attacker to rewrite than he expected it to be.


This seems wrong, the double spend attack's profitability depends strongly on how many confirms merchants are requiring and a bunch of other factors besides. And I don't even really understand the claim. Are you saying that a 1000BTC transaction isn't safe until 1000BTC of rewards and fees have been paid after it? That makes a certain sense I guess, but you still can't be sure because the attacker may be going back anyway to undo a 10k transaction in the block before.

edit: There was no need for me to be hyperbolic about buying thousands for GPUs. Each extra bit of hashing power I supply adds to the security of all previous transactions. The incentive mismatch I see is that those previous transactions don't pay me at all. I used to think that it would be unaesthetic and awkward to pay for each future confirm, but block finders paying miners to build off of their blocks handles all of this nicely.

I feel like I'm not getting across how important this is. I'm going to keep thinking and maybe write it all again if I think of a better way to explain.

The problem with otc imo is the IRC stuff. It took me several attempts to get a cloak and register a password and then I lost it and in a few attempts I still haven't been able to get it reset. I'm sure it works for some people, but you aren't going to get a majority of normal people to beg IRC mods for stuff all the time.

Obviously don't be the guy who trades $1000 with someone who's been trading $40s. But it's doubtful that all those $40s were setting up for a big $100 score. Also it's just one piece of info, if someone has 30 reasonable posts maybe you are undecided, but if they also did a trade 2 months ago w/ CoinPal for about the same amount they want to do with you now you are probably fine.

An options market would be nice. That could be provided directly or with a rep system.

Ah, yes, that makes sense. It's harder than I first thought.

But it isn't the case that no one will ever want to share PP. People who do PP transactions with others will be sharing it out of necessity. It would be some help to be able to link to proof that your PP email has had 8 successful CoinPal trades over the last 3 months.

Would it be reasonable to just have a transaction history page for each user and a check box to make it public and make that public page easy to link to? Is PGP stuff necessary?

Yes, it breaks the anonymity though and requires another layer of reputation and stuff.



I've been worried about that too. I think it boils down to getting your security by hoping there are fee tx coming after the block yours are in. Which isn't unreasonable, but it's a pretty variable level of security and it's hard to 'buy' more since your fee goes only to the first confirmation. 

The first pool did this to pay members directly and immediately. It's cool because that lets members verify that they are working on a block that will definitely pay them.

Okay, here is why I think this is important. It will be easiest to see if we skip to the far future, but I think it applies to some extent immediately and certainly around the 210000 block.

So it's the future and there is no block reward only fees. A particularly large number of fees come in and the block is solved and you hear about it. Now you could start working off of this block helping the miner who found it and the people who have transactions in it, but for what? There aren't yet any pending transactions, so you wait. Eventually enough transactions come in to make you start working, but in the meantime you have an idea. Keep working on your own version of the previous block, ignore the one that just came in. If you get a valid block you can always just pay others to work off of yours instead of the other one. This is what miners will do unless the previous block solver agrees to pass on part of his fees. This is entirely appropriate because each confirmation is a benefit to the transactions in this block. It would be annoying for regular users to pay multiple fees, but it looks to me like the miners have incentive to divvy them up 'correctly'.

I am confident that there is some way to handle the payment to the next block that builds on yours. If my thinking is right I have a feeling this may have been foreseen.

Is there possibly a way to commit to paying, but not actually pay for 120 blocks?

Alternatively, is it possible to include a transaction in only your block and if your block fails to be included ensure that that transaction can never be included in a later block. Like a do not-include-after-block-13204 switch or something?

I'm worried this doesn't work. The tx will be reissued if your block doesn't get taken and someone will get that fee later even if your block does not end up in the chain.

Still thinking.