Quote from: ByteCoin on July 19, 2010, 03:40:28 PM

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Thanks, ByteCoin - that is pretty much the sort of scenario I was considering. It sounds like it would be very hard to do, but it is possible. However, this would assume that:

1. The transaction was of a large enough value to make it all worth doing.
2. That the merchant does insufficient checking, considering the large value of the transaction.
3. That the attacker nodes can swamp the network sufficiently, that there would be no doubt that the attacker nodes appear to be the honest nodes.

I would say that 1 and 2 should be mutually exclusive - any large transfers would surely be checked thoroughly by the merchant. I would say that 3 would also be very difficult to do, without raising suspicion/alarm from the rest of the honest network*.

* This in itself is perhaps a DoS vulnerability - if honest nodes have a mechanism to flag an alarm if they fear the network is under attack, this could be mimicked by attack nodes as a denial of service attempt. It would only result in people refusing to transact during this period, which would surely not be worth the CPU power to do this, but still.

I think I'm sufficiently convinced in the theory, so it will be interesting to see how the system develops. I would imagine that while the system is small, but growing, such attacks may only be a matter of time away. We will then see how well the system copes, but I think it will do admirably well.