Subject: Re: [Bitcoin-development] Proposal: soft-fork to make anyone-can-spend outputs unspendable for 100 blocks

From: John Dillon <[email-masked]>
Date: Tue, 4 Jun 2013 14:55:36 +0000

> I'm one of the people experimenting in this area.  I've long argued
> that a zero-output transaction should be permitted -- 100% miner fee
> -- as an elegant proof of sacrifice.  Unfortunately that requires a
> hard fork.  Also, for most people, it seems likely that a change
> transaction would be generated.  That, then, would generate an
> already-standard transaction, where inputs > outputs.

100% miner fee is not a proof of anything because the miner could have created
that transaction for themselves. You must have proof that all miners had an
equal opportunity at collecting the fee, and the only way to do that is by
Peter's announce-commit protocol, or his unspendable until after n blocks
proposal.

Also the idea of a zero-output transaction is silly. In almost all cases you
are making the sarifice to link that act to an identity, and linking that act
to arbitrary data is far more flexible than any scheme relying on the pubkeys
that paid for the transaction. With a arbitrary data you can slice up the
sacrifice for instance with a merkle-sum-tree, as well as hide what the
sacrifice was for to preserve anonymity. The extra cost in size of the provably
unspendable OP_RETURN scriptPubKey is minimal for the rare time when it isn't
required.