Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 80E56C000A for ; Tue, 16 Mar 2021 06:10:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 6BDD54EC27 for ; Tue, 16 Mar 2021 06:10:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: 0.401 X-Spam-Level: X-Spam-Status: No, score=0.401 tagged_above=-999 required=5 tests=[BAYES_50=0.8, 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_DNSWL_LOW=-0.7, 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: smtp4.osuosl.org (amavisd-new); dkim=pass (1024-bit key) header.d=protonmail.com 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 8PWE0QMnMqyr for ; Tue, 16 Mar 2021 06:10:07 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mail-40130.protonmail.ch (mail-40130.protonmail.ch [185.70.40.130]) by smtp4.osuosl.org (Postfix) with ESMTPS id B80674EC1F for ; Tue, 16 Mar 2021 06:10:07 +0000 (UTC) Date: Tue, 16 Mar 2021 06:09:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail; t=1615875004; bh=FW2MdUsd1rGwCcSgCHFZ2Ouhc95UufsJ1FzQPe0+BZc=; h=Date:To:From:Reply-To:Subject:In-Reply-To:References:From; b=Js01VNXbUN64vCv4iHvb8db3dMas/MlKt9JCtgpneKeiPpb0MJkf4tjIpDEFEXFIH 12H2wz1WrF4Ux7H6UU/UJ5U3pYVa+l6AltGycfNFgBAB1y1L8AjfPm6iuqm94zowFf TpxZt5bLGZMn1QgYQ00u41QsgVmB5vrGexmlD100= To: Jeremy , Bitcoin Protocol Discussion From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [bitcoin-dev] Delegated signatures in Bitcoin within existing rules, no fork required 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: Tue, 16 Mar 2021 06:10:09 -0000 Good morning Jeremy, This is a very cool idea! > Multiple Delegates: By signing a txn with several delegate outputs, it is= possible to enforce multiple disparate conditions. Normally this is superf= luous -- why not just concatenate S1 and S2? The answer is that you may hav= e S1 require a relative height lock and S2 require a relative time lock (th= is was one of the mechanisms investigated for powswap.com). I am somewhat confused by this. Do you mean that the delegating transaction (the one signed using the scrip= t of A with `SIGHASH_NONE`) has as input (consumes) multiple delegate outpu= ts D1, D2... with individual scripts S1, S2... ? > Sequenced Contingent Delegation: By constructing a specific TXID that may= delegate the coins, you can make a coin's delegation contingent on some ot= her contract reaching a specific state. For example, suppose I had a contra= ct that had 100 different possible end states, all with fixed outpoints at = the end. I could delegate coins in different arrangements to be claimable o= nly if the contract reaches that state. Note that such a model requires som= e level of coordination between the main and observing contract as each Coi= n delegate can only be claimed one time. Does this require that each contract end-state have a known TXID at setup t= ime? > Redelegating: This is where A delegates to S, S delegates to S'. This typ= e of mechanism most likely requires the coin to be moved on-chain to the sc= ript (A OR S or S'), but the on-chain movement may be delayed (via presigne= d transactions) until S' actually wants to do something with the coin. The script `A || S || S'` suggests that delegation effectively still allows= the original owner to still control the coin, right? Which I suppose is implied by "Revocation" above. Regards, ZmnSCPxj