From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 44EA3C002B for ; Sat, 18 Feb 2023 18:04:03 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 1327A410B7 for ; Sat, 18 Feb 2023 18:04:03 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 1327A410B7 Authentication-Results: smtp4.osuosl.org; dkim=pass (2048-bit key) header.d=blockstream-com.20210112.gappssmtp.com header.i=@blockstream-com.20210112.gappssmtp.com header.a=rsa-sha256 header.s=20210112 header.b=MMGsE7JJ X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -1.899 X-Spam-Level: X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id JXRF9054rMJK for ; Sat, 18 Feb 2023 18:03:58 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 29CF340743 Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by smtp4.osuosl.org (Postfix) with ESMTPS id 29CF340743 for ; Sat, 18 Feb 2023 18:03:58 +0000 (UTC) Received: by mail-pg1-x531.google.com with SMTP id h21so482226pgv.9 for ; Sat, 18 Feb 2023 10:03:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blockstream-com.20210112.gappssmtp.com; s=20210112; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=7mmkk5zwvwDvLj3GzZUdYyLn+oTkFiBM09osCiNoL/E=; b=MMGsE7JJlM52dea7mOUmhYdquVRO2/3AcB3V/A5mOvumP4z+dJgHTPZ7n908h8jgx3 Nz8XfWjFVlydtSYVfWIsPbR6Ia7/8Tk7oAwD7YRPOzmDRTWeJccM9qaXPRaEQyc5qBUQ Cdze0T5mPz5rseSw/B3KgVruJSmLlLIhxQ28Y+i1nolCYeuepeukMrqTkaunD8xSG2ot Yc24ZVV6nyic3CtO+tEQ46jDZwEUuRoCdBz9E4acOt3etxUanTgOoKc798tCxK4mgevB aJzkSndGoYsJ/mqygGjEpiptbRL0GMVkN8RWSygcj4kUlfRAkn6xBXxTTGs5kBu6igCW 986g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7mmkk5zwvwDvLj3GzZUdYyLn+oTkFiBM09osCiNoL/E=; b=NuwDtXkASt2WbCUq1OPw6mxn//w6iG/oK0eUhnDvDkK/gYsFQiz3FKCWFWlhC8uftL t56q279ZmQLaBGMBk6lVFx/oi4+3PT1m4y+lqpA1/UzsRnW1Yen/SwZ+z2KASkcU+VpR w5ic2khxcLruFc5hfFtCvNMcvKEE0NwSnw78MRHNHtBWDx25Y79S7TAtGTaozEH7bget L6HHo4yhxJaaz4IY6ULjX0R8msU0LiYufuey+0I2KIf6hBzhk0KdrFfY+jp0LcgiYjeY lBevJRFHs7J6eYTcLKsvirMWxtwZx3XFwkvY7hhNQw/kXoGzrG5w2bGFfkrItKzpfZJD hQ3A== X-Gm-Message-State: AO0yUKXxXKzjl5BoOzUePp3O6xCz5jwaDhYDFhkvX5n23WkA2Bm0fSRr Ntm+92e8gdJIzn5QiFQAGdD4EDlgcTzQgHYYBla0ww== X-Google-Smtp-Source: AK7set8WfaD8E85Qextwaxas+j2B0F4/gducbF4pMYO5rto/gnUPWM+d81vLsVO3okEjSehOEq6T/l7hmbaMi7Ua5GI= X-Received: by 2002:a63:8f51:0:b0:4fc:2058:fa2b with SMTP id r17-20020a638f51000000b004fc2058fa2bmr987976pgn.3.1676743437392; Sat, 18 Feb 2023 10:03:57 -0800 (PST) MIME-Version: 1.0 References: <177848612-ad2b15230d78bcd732bbe8621af89a1e@pmq3v.m5r2.onet> In-Reply-To: <177848612-ad2b15230d78bcd732bbe8621af89a1e@pmq3v.m5r2.onet> From: "Russell O'Connor" Date: Sat, 18 Feb 2023 13:03:45 -0500 Message-ID: To: vjudeu@gazeta.pl, Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary="000000000000f742af05f4fd405b" Subject: Re: [bitcoin-dev] Testing censorship resistance of bitcoin p2p network X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Feb 2023 18:04:03 -0000 --000000000000f742af05f4fd405b Content-Type: text/plain; charset="UTF-8" On Sat, Feb 18, 2023 at 5:11 AM vjudeu via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > > Also, it gives us a hint, that if any Script upgrade will be considered in > the future, we can think about doing it in a way, where unused parts can be > pruned, without invalidating signatures. > FWIW, pruning unused case branches is a core design principle of the Simplicity language I am developing. That being said, even this is not enough to thwart agents that specifically desire to post unused data blobs as part of their programs. This is largely because there are many mathematical expressions for what is equivalently an identity function. Think computing (x ^ 257) mod 257 (see Fermat's little theorem). Even in Simplicity users can write Word **; unit which is roughly equivalent PUSH ** DROP in Script. I don't even bother trying to prevent it. Doing so just adds more consensus complexity, and only raises the bar slightly on how to work around it. Simplicity's pruning is instead meant as a way to (usually) lower costs for users who aren't actively trying to spam the network. --000000000000f742af05f4fd405b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Sat, Feb 18, 2023 at 5:11 AM vjudeu via bitcoin-dev <bitcoin-dev@lists.linuxfo= undation.org> wrote:

Also, it gives us a hint, that if any Script upgrade will be considered in = the future, we can think about doing it in a way, where unused parts can be= pruned, without invalidating signatures.

FWIW, pruning unused case branches is a core design principle of the Sim= plicity language I am developing.

That being said,= even this is not enough to thwart agents that specifically desire to post = unused data blobs as part of their programs.=C2=A0 This is largely because = there are many mathematical expressions for what is equivalently an identit= y function.=C2=A0 Think computing (x ^ 257) mod 257 (see Fermat's littl= e theorem).

Even in Simplicity users can write= Word <some data blob>; = unit which is roughly equivalent PUSH <data blob> DROP in Script.=C2=A0 I don't e= ven bother trying to prevent it.=C2=A0 Doing so just adds more consensus co= mplexity, and only raises the bar slightly on how to work around it.
<= div>
Simplicity's pruning is instead meant as a way to (u= sually) lower costs for users who aren't actively trying to spam the ne= twork.
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