Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id AB6F690 for ; Wed, 21 Oct 2015 08:49:37 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wi0-f172.google.com (mail-wi0-f172.google.com [209.85.212.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 09F5E8C for ; Wed, 21 Oct 2015 08:49:37 +0000 (UTC) Received: by wicll6 with SMTP id ll6so80384624wic.0 for ; Wed, 21 Oct 2015 01:49:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-type; bh=q3OIh/eUw9kfKo7R5UCxilbQMj52djP71Xjy9G7Ywhs=; b=yAX9aoyFf4DWPatWFz4pvm5vdP2QpDIr2sVdd49Hji6jc+UQU/ELZKH48G33ncDwl8 eamCpBDKC8f+ubOJazFyKDfEWU1DhL3CjTJehToZ7L/YHFm/9pSqd38qy3Jn+b1stWfl jZEVfDWAbdOvSFpKqhAJT0VC7NxlL5ljfwIj3VeH+sqHILIoM1dAV6rgnBQbh30TGM2w p4r+HwOmL8cl08F2Y+uepjpoZq/snZ44QDYKxlOH0pky/8vzvKLe2Hdx/HfuDfZK3vTg PMluSPm17SWDxr+lSScpvIdukiqVGQzFO+eDshh3/tPgifbvZEw1AqaXNw1HxWo+ROpm iaUA== X-Received: by 10.180.216.36 with SMTP id on4mr9765891wic.65.1445417375532; Wed, 21 Oct 2015 01:49:35 -0700 (PDT) MIME-Version: 1.0 References: <201510210618.56159.luke@dashjr.org> In-Reply-To: From: Christian Decker Date: Wed, 21 Oct 2015 08:49:26 +0000 Message-ID: To: Gregory Maxwell , Luke Dashjr Content-Type: multipart/alternative; boundary=001a1134c69c39128d052299754a X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] [BIP] Normalized transaction IDs X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Oct 2015 08:49:37 -0000 --001a1134c69c39128d052299754a Content-Type: text/plain; charset=UTF-8 On Wed, Oct 21, 2015 at 10:26 AM Gregory Maxwell wrote: > On Wed, Oct 21, 2015 at 7:48 AM, Gregory Maxwell > wrote: > > I'm still sad that uniform segregated witeness is so hard to deploy, > > adding another id to every utxo set won't be a nice cost. :( But I > > have been trying for a long time to come up with anything better and > > not being successful. > > Oh good. Luke solved it. > > To deploy SW without a disruptive flag day this encoding could be used: > > A new P2SH like scriptPubkey type is defined. In the soft-fork, the > scriptsig for this scriptPubkey is required to be empty. > > Signatures are not covered under txid, but carried along side. Then > committed to in blocks in a separate hashtree. > > Isn't that sort of what this BIP describes as well? Except that we use the scriptSig to transport the signatures internally to the transactions and strip them when it comes to signing/checking? The wire format and transport of transactions do not change so old clients continue to fetch and process transactions as before, they just can't verify the TX. Blocks still reference the instance but verification uses the stripped TX with the signatures on the side, etc. > The only disadvantage to the approach used in elements alpha that I > can come up with so far (in the few minutes since luke turned my can't > into a can) is that that the approach in EA did not disrupt the normal > relay handling process, and this would, since relay that transports > the extradata either needs to use a different hash that includes the > witness, or have a separate mechanism for witness transport. > --001a1134c69c39128d052299754a Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On Wed, Oct 21= , 2015 at 10:26 AM Gregory Maxwell <gmaxwell@gmail.com> wrote:
On Wed, Oct 21, 2015 at 7:48 AM, Gregory Maxwell <gmaxwell@gmail.com> wrote:
> I'm still sad that uniform segregated witeness is so hard to deplo= y,
> adding another id to every utxo set won't be a nice cost. :( But I=
> have been trying for a long time to come up with anything better and > not being successful.

Oh good. Luke solved it.

To deploy SW without a disruptive flag day this encoding could be used:

A new P2SH like scriptPubkey type is defined. In the soft-fork, the
scriptsig for this scriptPubkey is required to be empty.

Signatures are not covered under txid, but carried along side. Then
committed to in blocks in a separate hashtree.


Isn't that sort of what this BIP d= escribes as well? Except that we use the scriptSig to transport the signatu= res internally to the transactions and strip them when it comes to signing/= checking? The wire format and transport of transactions do not change so ol= d clients continue to fetch and process transactions as before, they just c= an't verify the TX. Blocks still reference the instance but verificatio= n uses the stripped TX with the signatures on the side, etc.
=C2= =A0
The only disadvantage to the approach used in elements alpha that I
can come up with so far (in the few minutes since luke turned my can't<= br> into a can) is that that the approach in EA did not disrupt the normal
relay handling process, and this would, since relay that transports
the extradata either needs to use a different hash that includes the
witness, or have a separate mechanism for witness transport.
--001a1134c69c39128d052299754a--