Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1SnCHi-0006Yn-Kg for bitcoin-development@lists.sourceforge.net; Fri, 06 Jul 2012 17:25:38 +0000 Received: from mail-gh0-f175.google.com ([209.85.160.175]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1SnCHh-0000ny-SN for bitcoin-development@lists.sourceforge.net; Fri, 06 Jul 2012 17:25:38 +0000 Received: by ghbz2 with SMTP id z2so9043325ghb.34 for ; Fri, 06 Jul 2012 10:25:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:x-originating-ip:in-reply-to:references:date :message-id:subject:from:to:cc:content-type:x-gm-message-state; bh=dLkMLJjN03MZ0Hl56n7eJznk0BOSb5S4POtAh9jOXzw=; b=jK3fAGCWoG8fOBnwyDUmPj+oxCC+Kd5nohtQcuAJSvAimyyDQHxHuNLDzH8X/TG3Qu mBnieE9obxEPVTAnMWPWUEjdayAaT072DOOM9p7q6YDmIhLANXNmJb34gFufFwvjDD+n 40bWGupACm7MyzKsTDkPvlGSIS2mGH5iziNC7nnAXIl36Jb1AFTWlyWrEc1XALs7Nw7K 90fjaFHmXVyVFv+4KXnV/2hD3hRqZ8y9mNTYyujNw8ZA2rfr4N5ERko4rYb49oyROL00 CmhDGF3J1YIxn49yEghm8DIcm7/aj18VXvbFkW3D9a0dna5zSdI+3TY51LUce8woesKl XO4g== MIME-Version: 1.0 Received: by 10.60.172.143 with SMTP id bc15mr31795350oec.73.1341593776548; Fri, 06 Jul 2012 09:56:16 -0700 (PDT) Received: by 10.76.101.167 with HTTP; Fri, 6 Jul 2012 09:56:16 -0700 (PDT) X-Originating-IP: [50.0.36.54] In-Reply-To: References: Date: Fri, 6 Jul 2012 09:56:16 -0700 Message-ID: From: Mark Friedenbach To: Jeff Garzik Content-Type: multipart/alternative; boundary=bcaec54c527c7beccd04c42c24ed X-Gm-Message-State: ALoCoQmwHViTw2CJKds9WdkXdj6ax8ZEKzXwHRYRbnWbdSqlodfxjAUtYi/etYlR11CwivDy8GTI X-Spam-Score: 1.0 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 1.0 HTML_MESSAGE BODY: HTML included in message X-Headers-End: 1SnCHh-0000ny-SN Cc: Bitcoin Development Subject: Re: [Bitcoin-development] BIP 34: Block v2, Height in Coinbase X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Jul 2012 17:25:38 -0000 --bcaec54c527c7beccd04c42c24ed Content-Type: text/plain; charset=UTF-8 On Fri, Jul 6, 2012 at 9:49 AM, Jeff Garzik wrote: > On Fri, Jul 6, 2012 at 12:45 PM, Peter Vessenes 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 refers to the first such pair that is not already spent. No? Mark --bcaec54c527c7beccd04c42c24ed Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, Jul 6, 2012 at 9:49 AM, Jeff Garzik <jgarzik@exmulti.com&g= t; wrote:
On Fri, Jul 6, 2012 at 12:45 PM, Peter Vessenes <peter@coinlab.com> wrote:
> The proposal is simple, and it's a small change for miners, I imag= ine.
>
> My question is: why?
>
> I worry about stuffing too many requirements on the coinbase. I suppos= e
> 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 th= is
> 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 incompatibl= e means. For example, mandate that a <transaction hash, output index>= refers to the first such pair that is not already spent. No?

Mark
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