From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 39922C000E for ; Mon, 5 Jul 2021 02:39:21 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 07ADE402AE for ; Mon, 5 Jul 2021 02:39:21 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -1.599 X-Spam-Level: X-Spam-Status: No, score=-1.599 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, FROM_LOCAL_NOVOWEL=0.5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: smtp2.osuosl.org (amavisd-new); dkim=pass (1024-bit key) header.d=protonmail.com Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jQN6BebjyAIQ for ; Mon, 5 Jul 2021 02:39:19 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mail-4318.protonmail.ch (mail-4318.protonmail.ch [185.70.43.18]) by smtp2.osuosl.org (Postfix) with ESMTPS id 610F4400B5 for ; Mon, 5 Jul 2021 02:39:19 +0000 (UTC) Date: Mon, 05 Jul 2021 02:39:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail; t=1625452754; bh=iy9jJGFM2xBqM9yDQu7Lk8Yl1SUvgrEUOW14AjbRpAU=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=OPoRwRRWNpUWLzTJloEXI9z2/m34gz3It209STdcNHsPYFZQyNxTSdGgE04kD8Pmm JpcFX2H5SughEqeRwNJhgrbMGh85wyXVKJFSeYSjWrPuUEiJ1Q03ClFbmV3Jpz66bR zLO9Bo624tKR30V5f/ZsagGJ2wSMHMtF/bQjjmGg= To: Russell O'Connor From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: In-Reply-To: References: <20210704011341.ddbiruuomqovrjn6@ganymede> <20210704203230.37hlpdyzr4aijiet@ganymede> <5keA_aPvmCO5yBh_mBQ6Z5SwnnvEW0T-3vahesaDh57f-qv4FbG1SFAzDvT3rFhre6kFl282VsxV_pynwn_CdvF7fzH2q9NW1ZQHPH1pmdo=@protonmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Unlimited covenants, was Re: CHECKSIGFROMSTACK/{Verify} BIP for Bitcoin 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: Mon, 05 Jul 2021 02:39:21 -0000 Good morning Russell, > On Sun, Jul 4, 2021 at 9:02 PM Russell O'Connor wrote: > > > Bear in mind that when people are talking about enabling covenants, we = are talking about whether OP_CAT should be allowed or not. > > > > That said, recursive covenants, the type that are most worrying, seems = to require some kind of OP_TWEAK operation, and I haven't yet seen any evid= ence that this can be simulated with CHECKSIG(FROMSTACK).=C2=A0 So maybe we= should leave such worries for the OP_TWEAK operation. > > Upon further thought, you can probably make recursive covenants even with= a fixed scritpubkey by sneaking the state into a few bits of the UTXO's am= ount.=C2=A0 Or if you try really hard, you may be able to stash your state = into a sibling output that is accessed via the txid embedded in the prevout= point. Which is kind of the point of avoiding giving too much power, because peopl= e can be very clever and start doing unexpected things from what you think = is already a limited subset. "Give an inch and they will take a mile". Still, as pointed out, altcoins already exist and are substantially worse, = and altcoin implementations are all going to run on Turing machines anyway = (which are powerful enough to offer Turing-machine functionality), so maybe= this is not really giving too much power, people can already fork Bitcoin = and add full EVM support on it. Regards, ZmnSCPxj