From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E069BB6D for ; Fri, 22 Sep 2017 22:09:08 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-yw0-f182.google.com (mail-yw0-f182.google.com [209.85.161.182]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 945B942D for ; Fri, 22 Sep 2017 22:09:08 +0000 (UTC) Received: by mail-yw0-f182.google.com with SMTP id w22so1633604ywa.13 for ; Fri, 22 Sep 2017 15:09:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=1ZgFkPV+PURn3+NwotisvoqnCGE4N1CkxfblNdQ7VIM=; b=fjECzd73QPjgCv1+soRlnMGuSWsthfa9NnwoUe73FpTKg7onkJy5jUKTT6HtAUmsMn 2H79Ta+G7G4k2D6M9TJpyXiECAVi3O+lnubDrlnD0Oae8uYydIzc7YpJAfwkL6FVTXcH wJsmNGYORKvzQnJ//To/J29rOgdBvNZUJIjpl/xJ4cp85MMHT/60UD7tv9EfoLkiMY4G 1kohDnU8mt8egbjJKfJwN634SutQEJqfv/HOWY9f4NcsUNWuSEhVOtfzc5yuCRwY6vbn 7X/dN1eumcXVoell/HMdlTYHp1wYi3l7Vdm25HeFirn+uXO2kDZQRglI7hBqCPfzvsBt OXHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=1ZgFkPV+PURn3+NwotisvoqnCGE4N1CkxfblNdQ7VIM=; b=fgno8oNv8FFo4g0LW/hhagyMzEdlZT2vMXdBfMi2SWhUM+3c9TxQzJ0rbHPYGGnQYv Kjkrrmzz/1Z5Z4No6KvlVHcCkfJuglYsdthB36kSWFEKRGFMO98UzYJIxNmelCD5+B8b HEYW33jYJ59vwggi9f6GTJ2FEmzEWOLQT/nC7bKS1hrIJ3iKZUKC6h/GpChPhtL86g5g VS9Og/jrh7CjQTETd5k0HXufdCGhzdxvYk3byFh3LYKTUEAgadD3KReTuX7pCI1N7LBC cnHB4xvfEY4cvQUU9mvZTH2M8mciB7na6O+5kHK3OKdCxpvN7h5Z26cbxjewINcH2OX2 VglA== X-Gm-Message-State: AHPjjUjOPfXfx4lLPxWAt8EYhxMCHWcjgjlasKz7Gahxfibh2q2csxK0 1rPFJ5i7GV9TGKET6Wkp+xjTqC/8WMJ7zZpJLpg= X-Google-Smtp-Source: AOwi7QApBjDnO3YOBIHohUR9lrgTfApygzfcxp/1HC7XMtHTxOZCq0/jeYIPEa+nbhPFXhU71n6+j3AWZouT+dVWB7Q= X-Received: by 10.129.162.82 with SMTP id z79mr382063ywg.98.1506118147629; Fri, 22 Sep 2017 15:09:07 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.80.80 with HTTP; Fri, 22 Sep 2017 15:09:07 -0700 (PDT) In-Reply-To: References: <5B6756D0-6BEF-4A01-BDB8-52C646916E29@friedenbach.org> <201709190309.08669.luke@dashjr.org> <3385CE20-C1BA-40DD-8FC3-8F53F3350717@friedenbach.org> <9FD4AF03-28A5-4B8A-9C12-CBCB1BC2E22C@friedenbach.org> From: Pieter Wuille Date: Fri, 22 Sep 2017 15:09:07 -0700 Message-ID: To: Sergio Demian Lerner , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary="94eb2c1282142deb0f0559ce7525" X-Spam-Status: No, score=0.4 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=disabled version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: Re: [bitcoin-dev] cleanstack alt stack & softfork improvements (Was: Merkle branch verification & tail-call semantics for generalized MAST) X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Sep 2017 22:09:09 -0000 --94eb2c1282142deb0f0559ce7525 Content-Type: text/plain; charset="UTF-8" On Fri, Sep 22, 2017 at 2:54 PM, Sergio Demian Lerner via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > If the variable size increase is only a few bytes, then three > possibilities arise: > > - one should allow signatures to be zero padded (to reach the maximum > size) and abandon strict DER encoding > > - one should allow spare witness stack elements (to pad the size to match > the maximum size) and remove the cleanstack rule. But this is tricky > because empty stack elements must be counted as 1 byte. > > - signers must loop the generation of signatures until the signature > generated is of its maximum size. > Or (my preference); - Get rid of DER encoding alltogether and switch to fixed size signatures. Cheers, -- Pieter --94eb2c1282142deb0f0559ce7525 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Fri, Sep 22, 2017 at 2:54 PM, Sergio Demian Lerner via = bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org= > wrote:
If the variable size incre= ase is only a few bytes, then three possibilities arise:

- one should allow signatures to be zero padded (to reach the maximum size= ) and abandon strict DER encoding

- one should all= ow spare witness stack elements (to pad the size to match the maximum size)= and remove the cleanstack rule. But this is tricky because empty stack ele= ments must be counted as 1 byte.

- signers must loop the= generation of signatures until the signature generated is of its maximum s= ize.

Or (my preference);<= /div>

- Get rid of DER encoding alltogether and switch t= o fixed size signatures.

Cheers,

--
Pieter

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