Quote from: phelix on May 19, 2013, 05:26:03 PM

Nodes could delay relaying of blocks including potential double spends (txs replacing txs the node knows about).

I would guess that major miners already are, or will, at some point, communicate directly among each other. After all, you don't want to miss a block.

It is not clear to me if one could not have a convention to under which miners might ignore certain blocks though.

Quote from: TalkingAntColony on May 19, 2013, 09:15:59 PM

I feel like this is a grey area with the proposal. You cannot simply assume there exists a feasible extension to scripting which would allow the network to verify that a double spend occurred.

I agree there is work need, but it is clear that there is a way of doing an extension which does what I want: simply introduce an opcode which does exactly what you want (i.e., don't even run the scripts; instead, check whether they have exactly the form required, and if so accept everything). Of course, this would be a bad way of doing it.

I think the main question here is: how can one make the scripting language flexible enough to allow this kind of mechanism?

Quote from: TalkingAntColony on May 19, 2013, 09:15:59 PM

Also, what happens when the payer double-spends to another merchant using this proposal's mechanism? Who's Tx3 would be valid?

Whichever is mined. Note that the miner will probably take the one giving him more fee.