Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id BFBE578D for ; Sun, 2 Oct 2016 23:00:19 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f51.google.com (mail-vk0-f51.google.com [209.85.213.51]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 26C84135 for ; Sun, 2 Oct 2016 23:00:18 +0000 (UTC) Received: by mail-vk0-f51.google.com with SMTP id y190so115417060vkd.3 for ; Sun, 02 Oct 2016 16:00:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blockstream-io.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=Ob6cwHhXhFhv9f/REMFKo4yqCV0Fap9OOumQdbunMMs=; b=PP5MJh55/rsCCeU8oLtH0wrufHsdofFqYNM4mm1kVj1Cd45F3JGaWpopqspGaol3jZ 7BzXHfmu6HiwYeKR3crPtFcu6rnF7xGxQUk3HnQdKlpOFcpECNplrwhw3w1hPXVGLPup gP3Uz/n2ErKq+zD8IM+7GYtJ4ipASEYek6N0bxFQRm/Gywv3jixrOHAnRYH9VubxPTxJ YR+VOMekOhcdpqkvm6dVbirAbICQvTqG92NmtZIY6/D0r14FZvKOJspCn7QkxoHNGdCE 6iMl3s9BH8P0KkNwF5k2CP3wO+yPeGbgtpHsrh0Hjh1+0NvIPemUbFfdhbCfT3sw2mxG QQGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=Ob6cwHhXhFhv9f/REMFKo4yqCV0Fap9OOumQdbunMMs=; b=SV8ge7F2805y2phoVj2y6sWaaL5iLX/hBNXYg9fhUs0gDKhukCij3CANd/p/URY7h2 zra1ToiXo6PXU/wShmM7/mzYnTyZwu7Kr9QoJ8t1M6T9ENSUpxgFL/nybCah2ojisewL kreSto6jJiLeQrToIlDT31XuViNKu6eFx97c1sl5xdd+j/maIjordDa5dgyTix3KBzIT 6BqpCkceTCsf91EJoHOwwWCKRKFLfsP8ng3Si7akQHqrxLwpnqLvOxW5NIhTTwvHVMF7 /jAFDGvEUO6UGCp6PsmSJZ9NJYSE662F6lI8bRfSR2lykB05FTgtanjN4tAsKuDE7n7l oiTQ== X-Gm-Message-State: AA6/9RkbJKm0jMGk8lODTCfSPfc8lCObiHkYXtqb9esbGMekQbxQuPsSocyOARREka78Am7cman++PakMUaVq3dD X-Received: by 10.31.34.68 with SMTP id i65mr12291253vki.77.1475449217062; Sun, 02 Oct 2016 16:00:17 -0700 (PDT) MIME-Version: 1.0 Received: by 10.176.3.102 with HTTP; Sun, 2 Oct 2016 16:00:16 -0700 (PDT) Received: by 10.176.3.102 with HTTP; Sun, 2 Oct 2016 16:00:16 -0700 (PDT) In-Reply-To: References: <20161002171137.GA18452@fedora-21-dvm> <201610022128.52401.luke@dashjr.org> From: "Russell O'Connor" Date: Sun, 2 Oct 2016 19:00:16 -0400 Message-ID: To: Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary=001a113dc8b477b3c8053de9ca55 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, 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: Sun, 02 Oct 2016 23:15:08 +0000 Subject: [bitcoin-dev] Fwd: Re: Drivechain proposal using OP_COUNT_ACKS 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: Sun, 02 Oct 2016 23:00:19 -0000 --001a113dc8b477b3c8053de9ca55 Content-Type: text/plain; charset=UTF-8 I forget to send to bitcoin-dev. > A related problem is that if this transaction is reorged out during an innocent reorg, one that doesn't involve a double spend, the transaction may never get back in unless it occurs at exactly the same height, which is not guaranteed. > > This affects fungabity of coins generated from these transactions. > > > On Oct 2, 2016 18:37, "Sergio Demian Lerner" wrote: >> >> >> >> On Sun, Oct 2, 2016 at 6:46 PM, Russell O'Connor via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: >>> >>> >>>> But I would argue that in this scenario, the only way it >>>> would become invalid is the equivalent of a double-spend... and therefore it >>>> may be acceptable in relation to this argument. >>> >>> >>> The values returned by OP_COUNT_ACKS vary in their exact value depending on which block this transaction ends up in. While the proposed use of this operation is somewhat less objectionable (although still objectionable to me), nothing stops users from using OP_EQUALVERIFY and and causing their transaction fluctuate between acceptable and unacceptable, with no party doing anything like a double spend. This is a major problem with the proposal. >> >> >> Transactions that redeem an output containing (or referencing by means of P2WSH) an OP_COUNT_ACKS are not broadcast by the network. That means that the network cannot be DoS attacked by flooding with a transaction that will not verify due to being too late. >> The only parties that can include the redeem transaction are the miners themselves. >> Therefore I see no problem that an OP_COUNT_ACKS scriptSig transaction is invalidated after the liveness times expires. >> If there is no expiration, then polls can last forever and the system fails to provide DoS protection for block validation since active polls can accumulate forever. >> >> >> --001a113dc8b477b3c8053de9ca55 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

I forget to send to bitcoin-dev.

> A related problem is that if this transaction is reorge= d out during an innocent reorg, one that doesn't involve a double spend= , the transaction may never get back in unless it occurs at exactly=C2=A0 t= he same height, which is not guaranteed.
>
> This affects fungabity of coins generated from these transactions.
>
>
> On Oct 2, 2016 18:37, "Sergio Demian Lerner" <sergio.d.lerner@gmail.com> wrote:<= br> >>
>>
>>
>> On Sun, Oct 2, 2016 at 6:46 PM, Russell O'Connor via bitcoin-d= ev <bitcoin-dev= @lists.linuxfoundation.org> wrote:
>>>
>>>
>>>> But I would argue that in this scenario, the only way it >>>> would become invalid is the equivalent of a double-spend..= . and therefore it
>>>> may be acceptable in relation to this argument.
>>>
>>>
>>> The values returned by OP_COUNT_ACKS vary in their exact value= depending on which block this transaction ends up in.=C2=A0 While the prop= osed use of this operation is somewhat less objectionable (although still o= bjectionable to me), nothing stops users from using OP_EQUALVERIFY and and = causing their transaction fluctuate between acceptable and unacceptable, wi= th no party doing anything like a double spend.=C2=A0 This is a major probl= em with the proposal.
>>
>>
>> Transactions that redeem an output containing (or referencing by m= eans of P2WSH) an OP_COUNT_ACKS are not broadcast by the network. That mean= s that the network cannot be DoS attacked by flooding with a transaction th= at will not verify due to being too late.
>> The only parties that can include the redeem transaction are the m= iners themselves.
>> Therefore I see no problem that an OP_COUNT_ACKS scriptSig transac= tion is invalidated after the liveness times expires.
>> If there is no expiration, then polls can last forever and the sys= tem fails to provide DoS protection for block validation since active polls= can accumulate forever.
>>
>>
>>

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