Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 15EDDCCA for ; Mon, 5 Feb 2018 20:01:27 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f44.google.com (mail-vk0-f44.google.com [209.85.213.44]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id B63261C0 for ; Mon, 5 Feb 2018 20:01:25 +0000 (UTC) Received: by mail-vk0-f44.google.com with SMTP id a63so18445592vkg.6 for ; Mon, 05 Feb 2018 12:01:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=RHG+A+PM+M8a5rEEEfLJUi5kpmkAA+BWCm74iuJNJw4=; b=ai0bo+FfMIq0GfxM0ZmdqnIauSVCC19PGkCrHzQlN9wxNnYasvrihI6NSPyPhlIw64 RF8H1FLatKVWD+fAagNGdRmbjk6RqnW7xQuAcOTHfVyAMAmcbtFLjoAw/CBnR51OzTiX /86py7FonI+eg7XNdiavAPjCXxdyRgoZlvkrS7PsBiY9UyvcAT8dj4WSN+9IpcHekZVp eTuZ04vsdQnwofHjA0vn4u2P/qnl4hC4ov6Altp5aLoFLuF6sIgA3dvo6/46yUtjAj7a CySLFDDfHH5vPOvZ56hOXWbVv/AHxDENNToE7qMMQL5jRMbdg0eTSm2/ebwuzWQAAug7 mM1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=RHG+A+PM+M8a5rEEEfLJUi5kpmkAA+BWCm74iuJNJw4=; b=OiQb9lYL/qZ1kSczlQYKtnHO6JqHIbAk6aBTz4z6ticish2OIQnrWDc+ROkROb4QM/ tx6iBRRb+lAU0w+8pCeuLvhxXjXN7AVl8UL+O1n9HhlWc1R5eaFw5fzq3xOwkVo38W9S YPxiiJ/2HWkb0gSt6h3nQIhUcaVtoWScBk4fw2ZYDkcakbGCIVts9SlNOwATk1VcbJ9z bTAkteceM9x5cjfh0869+5KLIIqtPhiUA8+1ClUff7DWoeMh705JwQEeu/2ZGJ6VH6VB 3CC0ldXB0X7kqJwrygpj5Y+gylQ2VgnFuj+e90XQD4UkfxSWkIU45uVOAzhfR32t1FNp ustQ== X-Gm-Message-State: AKwxyterky10UIgkUrSpk1AUXN/Zr1/y4uxm9uOwaEDroMPUR7PzYPgg bYbHlxphtc9tphGixwLw5KRD65EUxgJTzerZQAM= X-Google-Smtp-Source: AH8x224lX3JSdj9hkYijhUXu3N/ZpwIZ8pVsUtY1bBbrgvdxf+0AJvYUG+1adZGVZ2xQ3MSUPFpYt+kqxT6ye3/F1bw= X-Received: by 10.31.195.196 with SMTP id t187mr41864601vkf.182.1517860884031; Mon, 05 Feb 2018 12:01:24 -0800 (PST) MIME-Version: 1.0 Sender: gmaxwell@gmail.com Received: by 10.103.136.69 with HTTP; Mon, 5 Feb 2018 11:58:24 -0800 (PST) In-Reply-To: References: From: Gregory Maxwell Date: Mon, 5 Feb 2018 19:58:24 +0000 X-Google-Sender-Auth: zTe8jzI_NrxEWRs2-7DbWpl_8-8 Message-ID: To: Ryan Grant Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, FREEMAIL_FROM, 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 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Graftroot: Private and efficient surrogate scripts under the taproot assumption 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: Mon, 05 Feb 2018 20:01:27 -0000 On Mon, Feb 5, 2018 at 3:56 PM, Ryan Grant wrote: > Am I reading correctly that this allows unilateral key rotation (to a > previously unknown key), without invalidating the interests of other > parties in the existing multisig (or even requiring any on-chain > transaction), at the cost of storing the signed delegation? Yes, though I'd avoid the word rotation because as you note it doesn't invalidate the interests of any key, the original setup remains able to sign. You could allow a new key of yours (plus everyone else) to sign, assuming the other parties agree... but the old one could also still sign.