Return-Path: Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4BD0CC002D for ; Mon, 11 Jul 2022 10:28:54 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 26E9E82A28 for ; Mon, 11 Jul 2022 10:28:54 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 26E9E82A28 Authentication-Results: smtp1.osuosl.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.a=rsa-sha256 header.s=protonmail3 header.b=GutY8Qyg X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -0.202 X-Spam-Level: X-Spam-Status: No, score=-0.202 tagged_above=-999 required=5 tests=[BAYES_20=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8soy_hEhkgQU for ; Mon, 11 Jul 2022 10:28:53 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org D53A882A26 Received: from mail-40137.protonmail.ch (mail-40137.protonmail.ch [185.70.40.137]) by smtp1.osuosl.org (Postfix) with ESMTPS id D53A882A26 for ; Mon, 11 Jul 2022 10:28:52 +0000 (UTC) Date: Mon, 11 Jul 2022 10:28:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1657535330; x=1657794530; bh=6ePxGZ3PNGMJny3wu+JgU1tqoNxbE90WyYg+pAAZwIA=; h=Date:To:From:Reply-To:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID; b=GutY8QygHNTct8CiQmZKKBCZKJjQ9Y6W9RidOGNguTXVsFCWYtK0r0J/NtxIVM392 QppG8YRmIYuOFS1PvnU+xGvZtnlHMKskSyaeFWVQtqe8/jmVA4BNvQi7iLlCjIzZZH 5rc3AWuH1Ub6VwlPVCzCcQ97U/MI1MEvGi4LGx/qvmKlsr4zfCVdr48nOxrBVz8qSQ yQn/1CuxYBjjKnhRfiGmjrik3uBafE3T/mMfBw4xSOO992dFHKCa8EIZQicAxxzHJ5 z+zi7bcMZhReWIx+l/l4HAoREo20JpzTYUHdhi/68MPtrMG3dDFA0zYwiAZQ6Y7U3j XPvxUwhOUe4/Q== To: "bitcoin-dev@lists.linuxfoundation.org" From: Alfred Hodler Reply-To: Alfred Hodler Message-ID: <7MZupPo-je8mhyxtw-sPQ19zypYdoXmh93RoVCLVZ_yXo9bEnUChMFjKU6E4W9gpLXbGiHMlbxY05K62BCzrYuaiPVp_7YdxM1_J3ToSnGU=@protonmail.com> In-Reply-To: References: Feedback-ID: 44065311:user:proton MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Mon, 11 Jul 2022 13:59:03 +0000 Subject: Re: [bitcoin-dev] [BIP proposal] Private Payments 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, 11 Jul 2022 10:28:54 -0000 Update: Bob doesn't have to watch all address types he's advertising. When = notifying Bob, Alice will pick one address type out of the ones Bob is adve= rtising and include it in the notification. That way even if Bob's wallet a= ccepts many address types, he still doesn't have to watch all of them for e= ach Alice. The previous spec reads: > Alice then constructs a 72-byte OP_RETURN output whose value is set to `B= IPXXXX + notification + N_Alice` (`+` is concat) and sends it in a transact= ion containing no other outputs (XXXX to be replaced once a BIP number is a= ssigned). We can extended the payload to 73 bytes and define it as: `BIPXXXX + notifi= cation + N_Alice + address_type`, where `address_type` is a single byte con= taining the desired address type index (1 out of 16, limited by Bob's payme= nt code). If Alice ever wants to start sending to a different address type,= she can simply re-notify Bob and Bob will switch to a new address type in = the case of Alice. Alfred