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 EAC3498A for ; Wed, 5 Jul 2017 04:11:22 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from zinan.dashjr.org (zinan.dashjr.org [192.3.11.21]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 25EDCAD for ; Wed, 5 Jul 2017 04:11:22 +0000 (UTC) Received: from ishibashi.localnet (unknown [IPv6:2001:470:5:265:a45d:823b:2d27:961c]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id 5D77A38A2255; Wed, 5 Jul 2017 04:10:46 +0000 (UTC) X-Hashcash: 1:25:170705:shaolinfry@protonmail.ch::NgIeSfZaZzxLzCBa:anf2z X-Hashcash: 1:25:170705:bitcoin-dev@lists.linuxfoundation.org::hUcANtULv303sc2H:coSL+ From: Luke Dashjr To: shaolinfry Date: Wed, 5 Jul 2017 04:10:43 +0000 User-Agent: KMail/1.13.7 (Linux/4.9.16-gentoo; KDE/4.14.32; x86_64; ; ) References: <201707050350.53122.luke@dashjr.org> <00qcLaDJFDoC9D6644P_aLf7_n5B1pqCPj_c02QlqySsrJLsB6TZipXMD8L7l3lJcw5NoLP6dphCMruKJCIMkJUIDYbIw0iDd322vsNFmNw=@protonmail.ch> In-Reply-To: <00qcLaDJFDoC9D6644P_aLf7_n5B1pqCPj_c02QlqySsrJLsB6TZipXMD8L7l3lJcw5NoLP6dphCMruKJCIMkJUIDYbIw0iDd322vsNFmNw=@protonmail.ch> X-PGP-Key-Fingerprint: E463 A93F 5F31 17EE DE6C 7316 BD02 9424 21F4 889F X-PGP-Key-ID: BD02942421F4889F X-PGP-Keyserver: hkp://pgp.mit.edu MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201707050410.45217.luke@dashjr.org> X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD 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@lists.linuxfoundation.org" Subject: Re: [bitcoin-dev] Height based vs block time based thresholds 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: Wed, 05 Jul 2017 04:11:23 -0000 It's not pointless: it's a wake-up call for miners asleep "at the wheel", to ensure they upgrade in time. Not having a mandatory signal turned out to be a serious bug in BIP 9, and one which is fixed in BIP 148 (and remains a problem for BIP 149 as-is). Additionally, it makes the activation decisive and unambiguous: once the lock-in period is complete, there remains no question as to what the correct protocol rules are. It also enables deploying softforks as a MASF, and only upgrading them to UASF on an as-needed basis. Luke On Wednesday 05 July 2017 4:00:38 AM shaolinfry wrote: > Luke, > I previously explored an extra state to require signalling before > activation in an earlier draft of BIP8, but the overall impression I got > was that gratuitous orphaning was undesirable, so I dropped it. I > understand the motivation behind it (to ensure miners are upgraded), but > it's also rather pointless when miners can just fake signal. A properly > constructed soft fork is generally such that miners have to deliberately > do something invalid - they cannot be tricked into it... and miners can > always chose to do something invalid anyway. > > > -------- Original Message -------- > > From: luke@dashjr.org > > To: bitcoin-dev@lists.linuxfoundation.org, shaolinfry > > I"ve already opened a PR almost 2 weeks ago > > to do this and fix the other issues BIP 9 has. > > https://github.com/bitcoin/bips/pull/550 > > It just needs your ACK to merge. > > > > On Wednesday 05 July 2017 1:30:26 AM shaolinfry via bitcoin-dev wrote: > >> Some people have criticized BIP9"s blocktime based thresholds arguing > >> they are confusing (the first retarget after threshold). It is also > >> vulnerable to miners fiddling with timestamps in a way that could > >> prevent or delay activation - for example by only advancing the block > >> timestamp by 1 second you would never meet the threshold (although this > >> would come a the penalty of hiking the difficulty dramatically). On the > >> other hand, the exact date of a height based thresholds is hard to > >> predict a long time in advance due to difficulty fluctuations. However, > >> there is certainty at a given block height and it"s easy to monitor. If > >> there is sufficient interest, I would be happy to amend BIP8 to be > >> height based. I originally omitted height based thresholds in the > >> interests of simplicity of review - but now that the proposal has been > >> widely reviewed it would be a trivial amendment.