From: Rusty Russell <rusty@rustcorp.com.au>
To: Gavin Andresen <gavinandresen@gmail.com>,
	Gregory Maxwell <gmaxwell@gmail.com>
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Date: Thu, 24 Sep 2015 10:41:03 +0930
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Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Weak block thoughts...
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Gavin Andresen via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>
writes:
> I don't see any incentive problems, either. Worst case is more miners
> decide to skip validation and just mine a variation of the
> highest-fee-paying weak block they've seen, but that's not a disaster--
> invalid blocks will still get rejected by all the non-miners running full
> nodes.

That won't help SPV nodes, unfortunately.

> If we did see that behavior, I bet it would be a good strategy for a big
> hashrate miner to dedicate some of their hashrate to announcing invalid
> weak blocks; if you can get your lazy competitors to mine it, then you
> win....

We already see non-validating mining, but they do empty blocks.  This
just makes it more attractive in the future, since you can collect fees
too.

But I think it's clear we'll eventually need some UTXO commitment so
full nodes can tell SPV nodes about bad blocks.

Cheers,
Rusty.