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

From: Peter Todd <[email-masked]>
Date: Tue, 4 Jun 2013 16:25:18 -0400

On Tue, Jun 04, 2013 at 02:49:54PM -0400, Jeff Garzik wrote:
> On Tue, Jun 4, 2013 at 2:36 PM, Roy Badami <[email-masked]> wrote:
> >> Sure they are paying themselves, but given bitcoin network
> >> difficulty is uso high, simply obtaining payments-go-myself-as-miner
> >> transactions is itself difficult.
> >
> > Not for pool operators it isn't.  Nor for people buying hashing power
> > from a GPUMAX-type service, if such services still exist (or should
> > they exist again in future).
> 
> Re-read what I wrote.  That's perfectly OK.  It is analogous to a pool
> operator receiving merged mined coins, each time they mine a bitcoin
> block.
> 
> If you achieve the very high difficulty needed to create a valid
> bitcoin block, you have achieved a very high bar.

"High" is relative.

I could make a 100BTC apparently sacrifice via fees by just waiting a
month or two for my mining hardware to find a block that had a
pre-prepared fake sacrifice. It'd cost me roughly 1BTC when you take
orphans into account. Similarly I could hack into a pool and have them
do it on my behalf, or a pool could just offer the service for a fee.

I already worry enough that announce-commit sacrifices to mining fees
aren't secure enough given the potential of a few large pools teaming
up to create them cheaply, let alone what you're talking about...

Hey Luke: so what's the going rate to get Eligius to mine a fake mining
fee sacrifice? Can I get a discount on repeat orders? :)

-- 
'peter'[:-1]@petertodd.org
000000000000014c5bfacfca559fd6a9519dcd338f9fca6590eda7d156120013