<p dir="ltr">What is the advantage of this proposal over just orphaning the block with double spends?</p>
<p dir="ltr">There's currently a set of rules which government what constitutes a valid block. Miners don't build on blocks that don't accord with those rules out of fear that a major won't follow and they will waste hashing power.</p>
<p dir="ltr">If there was a rule supported by the majority that considered blocks with double spends (defined in some fashion) as invalid miners wouldn't build on them for the same reason they wouldn't build on a block with a coinbase over 25 btc, say. It seems that would accomplish the same without the other issues. </p>
<div class="gmail_quote">On Apr 23, 2014 12:04 PM, "Christophe Biocca" <<a href="mailto:christophe.biocca@gmail.com">christophe.biocca@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
It's not necessary that this "coinbase retribution" be either<br>
profitable or risk-free for this scheme to work. I think we should<br>
separate out the different layers of the proposal:<br>
<br>
1. Attacking the coinbase instead of orphaning allows for 100 blocks'<br>
time for a consensus to be reached, rather than 10 minutes. This<br>
allows for human verification/intervention if needed (orphaning<br>
decisions would almost always need to be automated, due to the short<br>
timeframe). This is a useful insight, and I don't think it's been<br>
brought up before.<br>
<br>
2. The original specification of how it's done (redistribution, no<br>
cost to voting) does seem exploitable. This can be fixed by reducing<br>
the incentive (burning instead of redistributing) and/or adding a risk<br>
to the orphaning attempts (a vote that fails destroys X bitcoins'<br>
worth from each voting block's own coinbase). The incentives can be<br>
tailored to mirror those of orphaning a block, to reduce the risk of<br>
abuse. Then the only difference from orphaning are 1) More limited<br>
rewriting of history (only the coinbase, vs all transactions in the<br>
block), and 2) More time to coordinate a response.<br>
<br>
3. This proposal may be used for things other than punishing<br>
double-spend pools. In fact it might be used to punish miners for<br>
doing anything a significant percentage of hashpower dislikes (large<br>
OP_RETURNs, large blocks, gambling transactions, transactions banned<br>
by a government). But we can make the threshold higher than 51%, so<br>
that this doesn't turn into a significant risk (if 75% of hashpower is<br>
willing to enforce a rule, we're already likely to see it enforced<br>
through orphaning).<br>
<br>
On Wed, Apr 23, 2014 at 11:38 AM, Alex Mizrahi <<a href="mailto:alex.mizrahi@gmail.com">alex.mizrahi@gmail.com</a>> wrote:<br>
><br>
>><br>
>> And it still would. Non-collusive miners cast votes based on the outcome<br>
>> of their own attempts to double spend.<br>
><br>
><br>
> Individually rational strategy is to vote for coinbase reallocation on every<br>
> block.<br>
><br>
> Yes, in that case nobody will get reward. It is similar to prisoner's<br>
> dilemma: equilibrium has worst pay-off.<br>
> In practice that would mean that simple game-theoretic models are no longer<br>
> applicable, as they lead to absurd results.<br>
><br>
>><br>
>> I'm using it in the same sense Satoshi used it. Honest miners work to<br>
>> prevent double spends. That's the entire justification for their existence.<br>
>> Miners that are deliberately trying to double spend are worse than useless.<br>
><br>
><br>
> Miners work to get rewards.<br>
> It absolutely doesn't matter whether they are deliberately trying to<br>
> double-spend or not: they won't be able to double-spend without a collusion.<br>
><br>
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