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| author | Praveen Baratam <praveen.baratam@gmail.com> | 2017-11-20 23:37:40 +0530 |
|---|---|---|
| committer | bitcoindev <bitcoindev@gnusha.org> | 2017-11-20 18:08:03 +0000 |
| commit | 4fdf808a2c4e2811f2a58f22c1a8dc34c6a9679c (patch) | |
| tree | ffca84527ffed2ec580bbda7834c3086aca8a5c2 /39 | |
| parent | a3dd32774f95148a1fd78f4d3e3a3911a5aa194a (diff) | |
| download | pi-bitcoindev-4fdf808a2c4e2811f2a58f22c1a8dc34c6a9679c.tar.gz pi-bitcoindev-4fdf808a2c4e2811f2a58f22c1a8dc34c6a9679c.zip | |
Re: [bitcoin-dev] Why SegWit Anyway?
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| -rw-r--r-- | 39/948aed7e3276104372da2232fc0a874779418a | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/39/948aed7e3276104372da2232fc0a874779418a b/39/948aed7e3276104372da2232fc0a874779418a new file mode 100644 index 000000000..f4ca6bb95 --- /dev/null +++ b/39/948aed7e3276104372da2232fc0a874779418a @@ -0,0 +1,212 @@ +Return-Path: <praveen.baratam@gmail.com> +Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org + [172.17.192.35]) + by mail.linuxfoundation.org (Postfix) with ESMTPS id 947E7C7C + for <bitcoin-dev@lists.linuxfoundation.org>; + Mon, 20 Nov 2017 18:08:03 +0000 (UTC) +X-Greylist: whitelisted by SQLgrey-1.7.6 +Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com [74.125.82.49]) + by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C16F9517 + for <bitcoin-dev@lists.linuxfoundation.org>; + Mon, 20 Nov 2017 18:08:02 +0000 (UTC) +Received: by mail-wm0-f49.google.com with SMTP id u83so12145792wmb.5 + for <bitcoin-dev@lists.linuxfoundation.org>; + Mon, 20 Nov 2017 10:08:02 -0800 (PST) +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=31T86SEjWa+G9+wZ54bOCrHrzYy2w/KxO+Sv9wG7P14=; + b=fUOhIA6qNLcfyr8ruf7kkUvbLtgupwGMo8d4cUclw4MbXuZxPujAr/xogGrSw24hvU + M26sqVfOW0oQQd6LYvzwI+X23xTM79tbkdeinX/ST6mhdC3BpqjSK+CDWjNS6rOy+/so + qbSnVxy0/xtDAyFzBdIO+DxuDO+Mmd1/uyNmo57vDwLIzuASOypERjOyqS92YaDVRFF8 + XnNjuzJjqJbrnSfAs9nBtahOdHtJwhpTs5m4wjPO0IUi8iZmWOXjr6hJLcanBb9TKxnY + cycKJy0tUBHtOU9PIUKJHPHWnZVir/sUnBOaHcY7onC434sQJEeu8GIEtvlE2ko5nCVa + b1iA== +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=31T86SEjWa+G9+wZ54bOCrHrzYy2w/KxO+Sv9wG7P14=; + b=PZd8iaIy00AzCufcgC2kEBQQ1zkeN3yM1mz1HQDhGgc6OVIfOOAp4uFbwbFmci/3V5 + KDuFGq1gWHJNVmeD2A8MnNyxJYSL6WAqpePqbZd5YjpQ8IDr0x2VA1b9gMjgeQjMxcBp + rT36oKwoFuTm7uqNzdNd2NTiwy8r2kZ3wdIan/vJwWQ4IaUhIPWXpq+Vi9oEpuRbhtZQ + zRrsL1+tuttonq0x98ax0zUyWdXlLaR09M6DbJZ2QfUN8AAmZrAR/pXApSFXrWupRGL7 + 4I4x+4Hjd6BvEI6Xpj4fSuaqPqr7AbL5KulZ0gR5mGryTJ7ya3NP9txoyHdOwldv6/f/ + RREw== +X-Gm-Message-State: AJaThX4jETeC4iYJZIhC5XhlJsUJs79fcohVWfluogZBOEF0cFfIwTga + FB9e4K1/sXpoUh1jKM9I8CCWcuVYBKBIBCHd52Y= +X-Google-Smtp-Source: AGs4zMbsWhDKS4129kdHxbSpFovoU2z6TWWU3lGj/F5TVXCahPVqMYCaddDkuHrbjm4jb4o7OlcydNeS3bRDZPv6a/k= +X-Received: by 10.28.212.69 with SMTP id l66mr10297391wmg.33.1511201281191; + Mon, 20 Nov 2017 10:08:01 -0800 (PST) +MIME-Version: 1.0 +Received: by 10.28.225.6 with HTTP; Mon, 20 Nov 2017 10:07:40 -0800 (PST) +In-Reply-To: <F392E62C-00CF-4D91-BB6B-706F2A59C63B@xbt.hk> +References: <CAAQs3wuDPktHc6kiZXqTaatOheX4KP=TRgje0_-ED5h8iNs-MA@mail.gmail.com> + <F392E62C-00CF-4D91-BB6B-706F2A59C63B@xbt.hk> +From: Praveen Baratam <praveen.baratam@gmail.com> +Date: Mon, 20 Nov 2017 23:37:40 +0530 +Message-ID: <CAAQs3wth=04PxDL6XzjTVYyZBiM1ZYHTK9-qRP8W+DAb53xMGg@mail.gmail.com> +To: Johnson Lau <jl2012@xbt.hk> +Content-Type: multipart/alternative; boundary="001a11469a608cb48a055e6df75f" +X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, + DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, + RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 +X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on + smtp1.linux-foundation.org +X-Mailman-Approved-At: Tue, 21 Nov 2017 13:06:37 +0000 +Cc: bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> +Subject: Re: [bitcoin-dev] Why SegWit Anyway? +X-BeenThere: bitcoin-dev@lists.linuxfoundation.org +X-Mailman-Version: 2.1.12 +Precedence: list +List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org> +List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>, + <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe> +List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/> +List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org> +List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help> +List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>, + <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe> +X-List-Received-Date: Mon, 20 Nov 2017 18:08:03 -0000 + +--001a11469a608cb48a055e6df75f +Content-Type: text/plain; charset="UTF-8" +Content-Transfer-Encoding: quoted-printable + +BIP 140 looks like it solves Tx Malleability with least impact on current +practices. It is still a soft fork though. + +Finally, if we were to create an alternative cyptocurrency similar to +Bitcoin, a Normalized Tx ID approach would be a better choice if I get it +right! +=E1=90=A7 + +On Mon, Nov 20, 2017 at 11:15 PM, Johnson Lau <jl2012@xbt.hk> wrote: + +> We can=E2=80=99t =E2=80=9Cjust compute the Transaction ID the same way th= +e hash for +> signing the transaction is computed=E2=80=9D because with different SIGHA= +SH flags, +> there are 6 (actually 256) ways to hash a transaction. +> +> Also, changing the definition of TxID is a hardfork change, i.e. everyone +> are required to upgrade or a chain split will happen. +> +> It is possible to use =E2=80=9Cnormalised TxID=E2=80=9D (BIP140) to fix m= +alleability +> issue. As a softfork, BIP140 doesn=E2=80=99t change the definition of TxI= +D. +> Instead, the normalised txid (i.e. txid with scriptSig removed) is used +> when making signature. Comparing with segwit (BIP141), BIP140 does not ha= +ve +> the side-effect of block size increase, and doesn=E2=80=99t provide any i= +ncentive +> to control the size of UTXO set. Also, BIP140 makes the UTXO set +> permanently bigger, as the database needs to store both txid and normalis= +ed +> txid +> +> On 21 Nov 2017, at 1:24 AM, Praveen Baratam via bitcoin-dev < +> bitcoin-dev@lists.linuxfoundation.org> wrote: +> +> Bitcoin Noob here. Please forgive my ignorance. +> +> From what I understand, in SegWit, the transaction needs to be serialized +> into a data structure that is different from the current one where +> signatures are separated from the rest of the transaction data. +> +> Why change the format at all? Why cant we just compute the Transaction ID +> the same way the hash for signing the transaction is computed? +> +> -- +> Dr. Praveen Baratam +> +> about.me <http://about.me/praveen.baratam> +> _______________________________________________ +> bitcoin-dev mailing list +> bitcoin-dev@lists.linuxfoundation.org +> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev +> +> +> + + +--=20 +Dr. Praveen Baratam + +about.me <http://about.me/praveen.baratam> + +--001a11469a608cb48a055e6df75f +Content-Type: text/html; charset="UTF-8" +Content-Transfer-Encoding: quoted-printable + +<div dir=3D"ltr">BIP 140 looks like it solves Tx Malleability with least im= +pact on current practices. It is still a soft fork though.<div><br></div><d= +iv>Finally, if we were to create an alternative cyptocurrency similar to Bi= +tcoin, a Normalized Tx ID approach would be a better choice if I get it rig= +ht!</div></div><div hspace=3D"streak-pt-mark" style=3D"max-height:1px"><img= + alt=3D"" style=3D"width:0px;max-height:0px;overflow:hidden" src=3D"https:/= +/mailfoogae.appspot.com/t?sender=3DacHJhdmVlbi5iYXJhdGFtQGdtYWlsLmNvbQ%3D%3= +D&type=3Dzerocontent&guid=3D1dc0cb1a-dc60-4b69-828a-6db933a55c26"><= +font color=3D"#ffffff" size=3D"1">=E1=90=A7</font></div><div class=3D"gmail= +_extra"><br><div class=3D"gmail_quote">On Mon, Nov 20, 2017 at 11:15 PM, Jo= +hnson Lau <span dir=3D"ltr"><<a href=3D"mailto:jl2012@xbt.hk" target=3D"= +_blank">jl2012@xbt.hk</a>></span> wrote:<br><blockquote class=3D"gmail_q= +uote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1e= +x"><div style=3D"word-wrap:break-word;line-break:after-white-space"><div>We= + can=E2=80=99t =E2=80=9Cjust compute the Transaction ID the same way the ha= +sh for signing the transaction is computed=E2=80=9D because with different = +SIGHASH flags, there are 6 (actually 256) ways to hash a transaction.</div>= +<div><br></div><div>Also, changing the definition of TxID is a hardfork cha= +nge, i.e. everyone are required to upgrade or a chain split will happen.</d= +iv><div><br></div>It is possible to use =E2=80=9Cnormalised TxID=E2=80=9D (= +BIP140) to fix malleability issue. As a softfork, BIP140 doesn=E2=80=99t ch= +ange the definition of TxID. Instead, the normalised txid (i.e. txid with s= +criptSig removed) is used when making signature. Comparing with segwit (BIP= +141), BIP140 does not have the side-effect of block size increase, and does= +n=E2=80=99t provide any incentive to control the size of UTXO set. Also, BI= +P140 makes the UTXO set permanently bigger, as the database needs to store = +both txid and normalised txid<br><div><div><br><blockquote type=3D"cite"><d= +iv><div class=3D"h5"><div>On 21 Nov 2017, at 1:24 AM, Praveen Baratam via b= +itcoin-dev <<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" tar= +get=3D"_blank">bitcoin-dev@lists.<wbr>linuxfoundation.org</a>> wrote:</d= +iv><br class=3D"m_-4649666739189099192Apple-interchange-newline"></div></di= +v><div><div><div class=3D"h5"><div dir=3D"ltr"><div><span style=3D"font-fam= +ily:Verdana,arial,sans-serif;font-size:14px">Bitcoin Noob here. Please forg= +ive my ignorance.</span></div><span style=3D"font-family:Verdana,arial,sans= +-serif;font-size:14px"><div><span style=3D"font-family:Verdana,arial,sans-s= +erif;font-size:14px"><br></span></div>From what I understand, in SegWit, th= +e transaction needs to be serialized into a data structure that is differen= +t from the current one where signatures are separated from the rest of the = +transaction data.</span><div><span style=3D"font-family:Verdana,arial,sans-= +serif;font-size:14px"><br></span></div><div><span style=3D"font-family:Verd= +ana,arial,sans-serif;font-size:14px">Why change the format at all? Why cant= + we just compute the Transaction ID the same way the hash for signing the t= +ransaction is computed?</span><br clear=3D"all"><div><br></div>-- <br><div = +class=3D"m_-4649666739189099192gmail_signature"><div style=3D"color:rgb(34,= +34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(255= +,255,255)">Dr. Praveen Baratam</div><div style=3D"color:rgb(34,34,34);font-= +family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)"><= +br></div><div style=3D"color:rgb(34,34,34);font-family:arial,sans-serif;fon= +t-size:13px;background-color:rgb(255,255,255)"><a href=3D"http://about.me/p= +raveen.baratam" style=3D"color:rgb(17,85,204)" target=3D"_blank">about.me</= +a></div></div> +</div></div></div></div> +______________________________<wbr>_________________<span class=3D""><br>bi= +tcoin-dev mailing list<br><a href=3D"mailto:bitcoin-dev@lists.linuxfoundati= +on.org" target=3D"_blank">bitcoin-dev@lists.<wbr>linuxfoundation.org</a><br= +><a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev"= + target=3D"_blank">https://lists.linuxfoundation.<wbr>org/mailman/listinfo/= +bitcoin-<wbr>dev</a><br></span></div></blockquote></div><br></div></div></b= +lockquote></div><br><br clear=3D"all"><div><br></div>-- <br><div class=3D"g= +mail_signature" data-smartmail=3D"gmail_signature"><div style=3D"color:rgb(= +34,34,34);font-family:arial,sans-serif;font-size:13px;background-color:rgb(= +255,255,255)">Dr. Praveen Baratam</div><div style=3D"color:rgb(34,34,34);fo= +nt-family:arial,sans-serif;font-size:13px;background-color:rgb(255,255,255)= +"><br></div><div style=3D"color:rgb(34,34,34);font-family:arial,sans-serif;= +font-size:13px;background-color:rgb(255,255,255)"><a href=3D"http://about.m= +e/praveen.baratam" style=3D"color:rgb(17,85,204)" target=3D"_blank">about.m= +e</a></div></div> +</div> + +--001a11469a608cb48a055e6df75f-- + |