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| author | vjudeu <vjudeu@gazeta.pl> | 2022-05-11 12:57:01 +0200 |
|---|---|---|
| committer | bitcoindev <bitcoindev@gnusha.org> | 2022-05-11 10:57:10 +0000 |
| commit | a2682073afd86e3526ad6b044eed1c5a293ca388 (patch) | |
| tree | 1deaebb6ca3dc60b6248299414b64f3551375e64 | |
| parent | 6568e35a12dda5c7e4f9c3d45f46c1b9c48585f1 (diff) | |
| download | pi-bitcoindev-a2682073afd86e3526ad6b044eed1c5a293ca388.tar.gz pi-bitcoindev-a2682073afd86e3526ad6b044eed1c5a293ca388.zip | |
Re: [bitcoin-dev] Speedy covenants (OP_CAT2)
| -rw-r--r-- | 12/4863e7249d4e82cf658a4a4d811dc5d24afbae | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/12/4863e7249d4e82cf658a4a4d811dc5d24afbae b/12/4863e7249d4e82cf658a4a4d811dc5d24afbae new file mode 100644 index 000000000..751b615e1 --- /dev/null +++ b/12/4863e7249d4e82cf658a4a4d811dc5d24afbae @@ -0,0 +1,129 @@ +Return-Path: <vjudeu@gazeta.pl> +Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) + by lists.linuxfoundation.org (Postfix) with ESMTP id 2E760C002D + for <bitcoin-dev@lists.linuxfoundation.org>; + Wed, 11 May 2022 10:57:10 +0000 (UTC) +Received: from localhost (localhost [127.0.0.1]) + by smtp3.osuosl.org (Postfix) with ESMTP id 0DB29610B9 + for <bitcoin-dev@lists.linuxfoundation.org>; + Wed, 11 May 2022 10:57:10 +0000 (UTC) +X-Virus-Scanned: amavisd-new at osuosl.org +X-Spam-Flag: NO +X-Spam-Score: -2.099 +X-Spam-Level: +X-Spam-Status: No, score=-2.099 tagged_above=-999 required=5 + tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, + DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, + SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no +Authentication-Results: smtp3.osuosl.org (amavisd-new); + dkim=pass (1024-bit key) header.d=gazeta.pl +Received: from smtp3.osuosl.org ([127.0.0.1]) + by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id qG7YtE2TqrUx + for <bitcoin-dev@lists.linuxfoundation.org>; + Wed, 11 May 2022 10:57:08 +0000 (UTC) +X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 +Received: from smtpo105.poczta.onet.pl (smtpo105.poczta.onet.pl + [213.180.149.158]) + by smtp3.osuosl.org (Postfix) with ESMTPS id C09D961079 + for <bitcoin-dev@lists.linuxfoundation.org>; + Wed, 11 May 2022 10:57:08 +0000 (UTC) +Received: from pmq1v.m5r2.onet (pmq1v.m5r2.onet [10.174.32.67]) + by smtp.poczta.onet.pl (Onet) with ESMTP id 4KysL53qxSzgcN; + Wed, 11 May 2022 12:57:01 +0200 (CEST) +DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gazeta.pl; s=2013; + t=1652266621; bh=5Za62nsdX/BUJy3N/DVtQHPO7SQH0kcpgdbt1WoOVYk=; + h=From:Cc:To:In-Reply-To:Date:Subject:From; + b=GzVGtLqbjI0ZIXdTrAyAhiN2nCAzxC95kPAWUJbg+x5po9bdLV31yMkcrzaLB+tgm + GmPLlHOCzrTMEqlDNk0infDgqYWT/E6HQ/M/LWpRDYS+88Yn7gX3ysMkqc/hAMuc0k + WM3DWLF35Xgdt6jEWyAoDnHBdQl7rBnzjFIFfSkA= +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: quoted-printable +Received: from [82.177.167.2] by pmq1v.m5r2.onet via HTTP id ; + Wed, 11 May 2022 12:57:01 +0200 +From: vjudeu@gazeta.pl +X-Priority: 3 +To: ZmnSCPxj <ZmnSCPxj@protonmail.com>,Nadav Ivgi <nadav@shesek.info> +In-Reply-To: <6pDae6X_tAfMTldPPsad5CSHPF98NVbTf06JxRCs7RqJGyrOqLALsDHHa_3C5DbbfpAVnzLMWCn-7e0FwQO-TOk4XxWYIiaYomuA9NJjkEQ=@protonmail.com> +Date: Wed, 11 May 2022 12:57:01 +0200 +Message-Id: <161946014-482cdec305e2bd7a2c3fc4774c70239d@pmq1v.m5r2.onet> +X-Mailer: onet.poczta +X-Onet-PMQ: <vjudeu@gazeta.pl>;82.177.167.2;PL;3 +X-Mailman-Approved-At: Wed, 11 May 2022 11:13:03 +0000 +Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org> +Subject: Re: [bitcoin-dev] Speedy covenants (OP_CAT2) +X-BeenThere: bitcoin-dev@lists.linuxfoundation.org +X-Mailman-Version: 2.1.15 +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: Wed, 11 May 2022 10:57:10 -0000 + +> Looks like `OP_CAT` is not getting enabled until after we are reasonably = +sure that recursive covenants are not really unsafe. + +Maybe we should use OP_SUBSTR instead of OP_CAT. Or even better: OP_SPLIT. = +Then, we could have OP_SPLIT <n> <pos1> <pos2> ... <posN> that would split = +a string N times (so there will be N+1 pieces). Or we could have just OP_SP= +LIT <pos> to split one string into two. Or maybe OP_2SPLIT and OP_3SPLIT, j= +ust to split into two or three pieces (as we have OP_2DUP and OP_3DUP). I t= +hink OP_SUBSTR or OP_SPLIT is better than OP_CAT, because then things alway= +s get smaller and we can be always sure that we will have one byte as the s= +mallest unit in our Script. + +On 2022-05-08 04:20:19 user ZmnSCPxj via bitcoin-dev <bitcoin-dev@lists.lin= +uxfoundation.org> wrote: +> Good morning shesek, + +> On Sat, May 7, 2022 at 5:08 PM ZmnSCPxj via bitcoin-dev <bitcoin-dev@list= +s.linuxfoundation.org> wrote: +> > * Even ***with*** `OP_CAT`, the following will enable non-recursive cov= +enants without enabling recursive covenants: +> > * `OP_CTV`, ... +> > * With `OP_CAT`, the following would enable recursive covenants: +> > * `OP_CHECKSIGFROMSTACK`, ... +> +> Why does CTV+CAT not enable recursive covenants while CSFS+CAT does? +> +> CTV+CAT lets you similarly assert against the outputs and verify that the= +y match some dynamically constructed script. +> +> Is it because CTV does not let you have a verified copy of the input's pr= +evout scriptPubKey on the stack [0], while with OP_CSFS you can because the= + signature hash covers it? +> +> But you don't actually need this for recursion. Instead of having the use= +r supply the script in the witness stack and verifying it against the input= + to obtain the quine, the script can simply contain a copy of itself as an = +initial push (minus this push). You can then reconstruct the full script qu= +ine using OP_CAT, as a PUSH(<script>) followed by the literal <script>. + + <OP_PUSH_length-of-script> OP_SWAP OP_DUP OP_CAT OP_CAT <rest of script= +...> + +Ha, yes, looks like you are correct here. + +`OP_CAT` makes *all* covenant opcodes recursive, because you can always qui= +ne using `OP_CAT`. + +By itself it does not make recursive covenants, but with probably any opcod= +e it would. + +Looks like `OP_CAT` is not getting enabled until after we are reasonably su= +re that recursive covenants are not really unsafe. + +Regards, +ZmnSCPxj +_______________________________________________ +bitcoin-dev mailing list +bitcoin-dev@lists.linuxfoundation.org +https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev + + |