You are right of course. This will work. I like this idea more
than my own proposed fix, as it doesn’t make any big changes to the economics of
the system in the way that burning would have.
Subject: Re: [Bitcoin-development] New attack identified and
potential solution described: Dropped-transaction spam attack against the block
size limit
That does sound good on the surface, but how do we enforce #1 and
#2? They seem to be unenforceable, as a miner can adjust the size of the
memory pool in his local source.
It doesn't have to be enforced. As long as a reasonable percentage of hash
rate is following that policy an attacker that tries to flood the network will
fail to prevent normal transaction traffic from going through and will just end
up transferring some wealth to the miners.
Although the existing default mining policy (which it seems about 70% of
hashpower follows) of setting aside some space for high-priority transactions
regardless of fee might also be enough to cause this attack to fail in
practice.