Subject: Re: [Bitcoin-development] BIP 34: Block v2, Height in Coinbase

From: Mark Friedenbach <[email-masked]>
Date: Fri, 6 Jul 2012 09:56:16 -0700

On Fri, Jul 6, 2012 at 9:49 AM, Jeff Garzik <[email-masked]> wrote:

> On Fri, Jul 6, 2012 at 12:45 PM, Peter Vessenes <[email-masked]> wrote:
> > The proposal is simple, and it's a small change for miners, I imagine.
> >
> > My question is: why?
> >
> > I worry about stuffing too many requirements on the coinbase. I suppose
> > the coinbase is easily extendible if we run out of bytes, but I think I'd
> > like to see some more discussion / good / bad type cases for making this
> > change. What do we get over just the prev_hash by doing this?
>
> With the existing setup (sans height in coinbase), you might not have
> unique transactions, with all that entails.
>

But those issues are solvable through other, non-backwards incompatible
means. For example, mandate that a <transaction hash, output index> refers
to the first such pair that is not already spent. No?

Mark