From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id EA20CC002D for ; Wed, 12 Oct 2022 09:04:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id B6B69417F7 for ; Wed, 12 Oct 2022 09:04:46 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org B6B69417F7 Authentication-Results: smtp4.osuosl.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.a=rsa-sha256 header.s=protonmail3 header.b=SejR7d// X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.102 X-Spam-Level: X-Spam-Status: No, score=-2.102 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, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_PASS=-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 QWxwwLZZfbNn for ; Wed, 12 Oct 2022 09:04:45 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 4CAF6417E0 Received: from mail-40135.protonmail.ch (mail-40135.protonmail.ch [185.70.40.135]) by smtp4.osuosl.org (Postfix) with ESMTPS id 4CAF6417E0 for ; Wed, 12 Oct 2022 09:04:45 +0000 (UTC) Date: Wed, 12 Oct 2022 09:04:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1665565483; x=1665824683; bh=wsG9b+GevHxMfQOXLNS4S8Zjku//UFCE1QWOVvKKieg=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID; b=SejR7d//H3qBXnUulUpsPDI/QbFF6bCeV4OqdGYeMHHGaXYV2WT4sNdJYiM5LrWIZ BkjgJUclOTg9ZX2bfybB8uahcVdD5jz93cJpMDWqPgolQEm60unu70loEVajFPf7n4 aJuO6moEpisEPUao1TtOQWFvrhIAjATTA9F24XQKEe7Nt0T57Qx0gYHzuU8B1AJXvp r9aWtSnG04D0q0K5s+oGjd3sp/7WRGlZItscLQklAjRx/PR75rxRUdIPC/lcr9CTnf qJAm8DFIPiyzUV1Qp7FLXThAnd0lYEq5h8MPDKIPMGMi9Y8HFuSMf6kcc3LtwAGXzh c/VTEZVjSmUOw== To: woltx From: alicexbt Message-ID: In-Reply-To: References: Feedback-ID: 40602938:user:proton MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Wed, 12 Oct 2022 11:41:32 +0000 Cc: "bitcoin-dev@lists.linuxfoundation.org" Subject: Re: [bitcoin-dev] Silent Payment v4 (coinjoin support added) 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: Wed, 12 Oct 2022 09:04:47 -0000 Hi=C2=A0woltx, Thanks for working on silent payments improving it in each version. 1) All inputs being used sounds good although I do not understand how it wo= uld benefit coinjoin. 2) New RPC command name is better. > I opened a new PR (#1143) to add a function to convert from x-only to com= pressed public key with even y.=20 Not sure about the concerns expressed by Andrew Poelstra in the pull reques= t related to rogue-key attacks. > Tutorial updated: https://gist.github.com/w0xlt/c81277ae8677b6c0d3dd07389= 3210875 > "warnings": "This address is not a new identity. It is a re-use of an exi= sting identity with a different label." I could not understand the warning in the output for `getsilentaddress` RPC= when used with a label. /dev/fd0 Sent with Proton Mail secure email. ------- Original Message ------- On Tuesday, October 11th, 2022 at 12:32 PM, woltx via bitcoin-dev wrote: > Silent Payment v4 (coinjoin support added) > Changes: >=20 > . Silent payments now use all inputs to create transactions. Previously, = they only used the first input. This change increases privacy and makes sil= ent payments compatible with coinjoin. >=20 > . `getspaddress` RPC renamed to `getsilentaddress` for clarity >=20 > . Added support for silent payment in PSBT via `walletcreatefundedpsbt` R= PC. >=20 > . Added a new index scheme (which stores the sum of input public keys for= each transaction). The previous index `bitcoin/signet/indexes/silentpaymen= tindex` should be removed as it is no longer compatible with this new versi= on. >=20 > For reviewers: >=20 > Now, silent payments use the scheme `hash(i1*X + i2*X + i3*X + ...)*G + X= =3D=3D hash(x*(I1+I2+I3+...))*G + X`, as described here: https://gist.gith= ub.com/RubenSomsen/c43b79517e7cb701ebf77eec6dbb46b8#variant-using-all-input= s >=20 > As inputs can be Taproot, this introduced a new issue as `bitcoin-core/se= cp256k1` does not support x-only public key sum (perhaps due to missing pre= fix byte). >=20 > I opened a new PR (#1143) to add a function to convert from x-only to com= pressed public key with even y. This is the solution being used by the curr= ent silent payment implementation. >=20 > Tutorial updated: https://gist.github.com/w0xlt/c81277ae8677b6c0d3dd07389= 3210875