Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 9F9C81EF0 for ; Wed, 7 Oct 2015 16:26:24 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from d.mail.sonic.net (d.mail.sonic.net [64.142.111.50]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 54DA3220 for ; Wed, 7 Oct 2015 16:26:24 +0000 (UTC) Received: from [192.168.1.190] (63.135.62.197.nwinternet.com [63.135.62.197] (may be forged)) (authenticated bits=0) by d.mail.sonic.net (8.15.1/8.15.1) with ESMTPSA id t97GQJup026445 (version=TLSv1 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Wed, 7 Oct 2015 09:26:20 -0700 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: multipart/signed; boundary="Apple-Mail=_C6132DD6-D156-4DA2-878D-4C3DB63ACAA5"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5.2 From: "Jonathan Toomim (Toomim Bros)" In-Reply-To: Date: Wed, 7 Oct 2015 09:26:24 -0700 Message-Id: References: <20150927185031.GA20599@savin.petertodd.org> <20151007150014.GA21849@navy>

To: Eric Lombrozo X-Mailer: Apple Mail (2.1878.6) X-Sonic-CAuth: UmFuZG9tSVZzpQnsiqsvN1Pq7x9vBGsS7iHRiS4gdNMS37UiWtNx85GzDPfoHYMGX3PpQI1NT+lkEafxiFg1kO9ON/aOxEXi X-Sonic-ID: C;EAPiIxBt5RG2e+K7sH9FTg== M;CtNTJBBt5RG2e+K7sH9FTg== X-Sonic-Spam-Details: 0.0/5.0 by cerberusd X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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: "Jonathan Toomim \(Toomim Bros\) via bitcoin-dev" , Anthony Towns Subject: Re: [bitcoin-dev] Let's deploy BIP65 CHECKLOCKTIMEVERIFY! 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, 07 Oct 2015 16:26:24 -0000 --Apple-Mail=_C6132DD6-D156-4DA2-878D-4C3DB63ACAA5 Content-Type: multipart/alternative; boundary="Apple-Mail=_633178B0-7663-4EDE-9A99-782901C7557E" --Apple-Mail=_633178B0-7663-4EDE-9A99-782901C7557E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On Oct 7, 2015, at 9:02 AM, Eric Lombrozo wrote: > But a real hashpower supermajority would make such attacks hard to = pull off in practice. If you had a 99% hashpower supermajority on the new version, an attacker = would still be able to perform this attack once per day. Since the = attacker is creating a transaction which is invalid according to new = clients, it will just sit around in old clients' mempool until one of = them mines a block. --Apple-Mail=_633178B0-7663-4EDE-9A99-782901C7557E Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii

On Oct 7, 2015, at 9:02 = AM, Eric Lombrozo <elombrozo@gmail.com> = wrote:

But a real hashpower supermajority = would make such attacks hard to pull off in = practice.

If you had a 99% hashpower = supermajority on the new version, an attacker would still be able to = perform this attack once per day. Since the attacker is creating a = transaction which is invalid according to new clients, it will just sit = around in old clients' mempool until one of them mines a = block.

= --Apple-Mail=_633178B0-7663-4EDE-9A99-782901C7557E-- --Apple-Mail=_C6132DD6-D156-4DA2-878D-4C3DB63ACAA5 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQEcBAEBCgAGBQJWFUewAAoJEIEuMk4MG0P10hsH/0ipsO0r9vk7JCKbh0b7z0Me +zJAjYGaB4YOHNv/3GMe1BbhbKiHhAgo5KKzbP02Sd0w+R0dNhhP3angLwpYwpFM Tm6MaHmloMcMb9qqsIrx3Z3muVJlNx+qC6x67vRGiq0Nv8JFqL7uFArxpBUnlBWK KhrzNwrCHFxhiYU4uOlgtUJMinUF1TAAQdOd/g55UPbl8feBYgNeWQpZFRIJJJgF 4NQeZgngGFUUMmNbaPi6+VTxWNb0U7kZrQMsgXkS8RSSgsoSKwKrI31tJ3AOmFQh Z6xZfo8lZ6HmyxLkyaotXh723ZTX+DYjJMkJURp83+YzkpBCerTRMqnFZUJxMzs= =lxA3 -----END PGP SIGNATURE----- --Apple-Mail=_C6132DD6-D156-4DA2-878D-4C3DB63ACAA5--