Return-Path: <1240902@gmail.com> Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 1117112C7 for ; Thu, 17 Sep 2015 22:33:21 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-io0-f176.google.com (mail-io0-f176.google.com [209.85.223.176]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 6F0ED204 for ; Thu, 17 Sep 2015 22:33:20 +0000 (UTC) Received: by ioiz6 with SMTP id z6so38242793ioi.2 for ; Thu, 17 Sep 2015 15:33:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=x4E2V4Ho8wTXI8VtcSJlGMqZv/EhSktBUHYQTLUbSc0=; b=R0ArP+pribNdOsTJkngg8LA3CdTTh1e0daqWU0VArwvoAPtZg6xMj6Gk7LHSJgm+mH XA/bXKTmDTdMDM2uJXeJjQALVAOHf/KbWWWCGQmH4fSlFdt5C0k4xaCsCD6uundvhmWR 1aMZDNcOVBw+61LTvTbAUAnymeVCBm3IpZjRSKgKkdcYBu7tt/A0oEKua6+g6rlYfVSE fmbHd/ypqSFpaPiRdMKcx8IPAhT3OH71jRv2MZcJ+my8Dr5Ikwr7Rj0wUnut5cgjDa6m 6OpeOb3Ba/GreDa3cxKwM+goAXUFLnm2IIoBdpNth/UzzQnFgQVwNSKUGdhJks5di9z9 mcmg== MIME-Version: 1.0 X-Received: by 10.107.129.65 with SMTP id c62mr11665709iod.4.1442529199900; Thu, 17 Sep 2015 15:33:19 -0700 (PDT) Received: by 10.107.135.71 with HTTP; Thu, 17 Sep 2015 15:33:19 -0700 (PDT) In-Reply-To: References: Date: Fri, 18 Sep 2015 06:33:19 +0800 Message-ID: From: Chun Wang <1240902@gmail.com> To: jl2012@xbt.hk Content-Type: text/plain; charset=UTF-8 X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM, 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@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] Fill-or-kill transaction 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: Thu, 17 Sep 2015 22:33:21 -0000 We are currently using nLockTime for share info and nSequence for extranonce2. I have carefully reviewed the reference implementation of BIP68 and it should be compatible, but this proposal may break the implementation unless it does not affect coinbase transactions. On Fri, Sep 18, 2015 at 2:41 AM, jl2012 via bitcoin-dev wrote: > Fill-or-kill tx is not a new idea and is discussed in the Scaling Bitcoin > workshop. In Satoshi's implementation of nLockTime, a huge range of > timestamp (from 1970 to 2009) is wasted. By exploiting this unused range and > with compromise in the time resolution, a fill-or-kill system could be built > with a softfork. > > ----------- > Two new parameters, nLockTime2 and nKillTime are defined: > > nLockTime2 (Range: 0-1,853,010) > 0: Tx could be confirmed at or after block 420,000 > 1: Tx could be confirmed at or after block 420,004 > . > . > 719,999: Tx could be confirmed at or after block 3,299,996 (about 55 years > from now) > 720,000: Tx could be confirmed if the median time-past >= 1,474,562,048 > (2016-09-22) > 720,001: Tx could be confirmed if the median time-past >= 1,474,564,096 > (2016-09-22) > . > . > 1,853,010 (max): Tx could be confirmed if the median time-past >= > 3,794,966,528 (2090-04-04) > > nKillTime (Range: 0-2047) > if nLockTime2 < 720,000, the tx could be confirmed at or before block > (nLockTime2 + nKillTime * 4) > if nLockTime2 >= 720,000, the tx could be confirmed if the median time-past > <= (nLockTime2 - 720,001 + nKillTime) * 2048 > > Finally, nLockTime = 500,000,000 + nKillTime + nLockTime2 * 2048 > > Setting a bit flag in tx nVersion will activate the new rules. > > The resolution is 4 blocks or 2048s (34m) > The maximum confirmation window is 8188 blocks (56.9 days) or 16,769,024s > (48.5 days) > > For example: > With nLockTime2 = 20 and nKillTime = 100, a tx could be confirmed only > between block 420,080 and 420,480 > With nLockTime2 = 730,000 and nKillTime = 1000, a tx could be confirmed only > between median time-past of 1,495,042,048 and 1,497,090,048 > > ---------------- > Why is this a softfork? > > Remember this formula: nLockTime = 500,000,000 + nKillTime + nLockTime2 * > 2048 > > For height based nLockTime2 (<= 719,999) > > For nLockTime2 = 0 and nKillTime = 0, nLockTime = 500,000,000, which means > the tx could be confirmed after 1970-01-01 with the original lock time rule. > As the new rule does not allow confirmation until block 420,000, it's > clearly a softfork. > > It is not difficult to see that the growth of nLockTime will never catch up > nLockTime2. > > At nLockTime2 = 719,999 and nKillTime = 2047, nLockTime = 1,974,559,999, > which means 2016-09-22. However, the new rule will not allow confirmation > until block 3,299,996 which is decades to go > > > > For time based nLockTime2 (> 720,000) > > For nLockTime2 = 720,000 and nKillTime = 0, nLockTime = 1,974,560,000, which > means the tx could be confirmed after median time-past 1,474,560,000 > (assuming BIP113). However, the new rule will not allow confirmation until > 1,474,562,048, therefore a soft fork. > > For nLockTime2 = 720,000 and nKillTime = 2047, nLockTime = 1,974,562,047, > which could be confirmed at 1,474,562,047. Again, the new rule will not > allow confirmation until 1,474,562,048. The 1 second difference makes it a > soft fork. > > Actually, for every nLockTime2 value >= 720,000, the lock time with the new > rule must be 1-2048 seconds later than the original rule. > > For nLockTime2 = 1,853,010 and nKillTime = 2047, nLockTime = 4,294,966,527, > which is the highest possible value with the 32-bit nLockTime > > ---------------- > User's perspective: > > A user wants his tx either filled or killed in about 3 hours. He will set a > time-based nLockTime2 according to the current median time-past, and set > nKillTime = 5 > > A user wants his tx get confirmed in the block 630000, the first block with > reward below 10BTC. He is willing to pay high fee but don't want it gets > into another block. He will set nLockTime2 = 210,000 and nKillTime = 0 > > ---------------- > OP_CLTV > > Time-based OP_CLTV could be upgraded to support time-based nLockTime2. > However, height-based OP_CLTV is not compatible with nLockTime2. To spend a > height-based OP_CLTV output, user must use the original nLockTime. > > We may need a new OP_CLTV2 which could verify both nLockTime and nLockTime2 > > ---------------- > 55 years after? > > The height-based nLockTime2 will overflow in 55 years. It is very likely a > hard fork will happen to implement a better fill-or-kill system. If not, we > could reboot everything with another tx nVersion for another 55 years. > > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev