Return-Path: Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 33F47C013E for ; Sat, 22 Feb 2020 12:11:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 1AC3C8550C for ; Sat, 22 Feb 2020 12:11:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RYlcgq19qhGd for ; Sat, 22 Feb 2020 12:10:59 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail1.protonmail.ch (mail1.protonmail.ch [185.70.40.18]) by hemlock.osuosl.org (Postfix) with ESMTPS id 41EB0854E7 for ; Sat, 22 Feb 2020 12:10:59 +0000 (UTC) Date: Sat, 22 Feb 2020 12:10:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=default; t=1582373456; bh=C4ClZiaCW5Tn5XqHML20JLE0pYbpHnbCugEVfccv9wc=; h=Date:To:From:Reply-To:Subject:In-Reply-To:References:Feedback-ID: From; b=adUWIcqe5kKULRUKLblzYxvhRDKz8zvYwNWH2+QqjTxVh6KUMGMPqW4uA/txd5Rba tQW/7HE7FgORDBDlh12Dii5bCPLyCI5J8CoS+YMhViS/FSbNqAGj4KyE5XgioLQ+Xw OCkolgDdhsjN1IFCkVaJVXiWlc/om+4PQTJOaRQo= To: Antoine Riard , Bitcoin Protocol Discussion From: AdamISZ Reply-To: AdamISZ Message-ID: In-Reply-To: References: Feedback-ID: bXDrzvuRufYtwlP51LbX1U1HVhop5RoBgHwub9Drp1-jSqeBk7WF1gtL3tVf_bUUZyA1LgUYiqtef7oP8A2trw==:Ext:ProtonMail MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Sat, 22 Feb 2020 14:15:28 +0000 Subject: Re: [bitcoin-dev] LN & Coinjoin, a Great Tx Format Wedding 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: Sat, 22 Feb 2020 12:11:01 -0000 =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original Me= ssage =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 On Friday, 21 February 2020 22:17, Antoine Riard via bitcoin-dev wrote: > How can a Bitcoin tranaction leak protocol usage ? > * the output type (p2sh, p2wsh, ...) > * the spending policy (2-of-3 multisig, timelock, hashlock,...) > * outputs ordering (BIP69) > * nLocktime/nSequence > * RBF-signaling > * Equal-value outputs > * weird watermark (LN commitment tx obfuscated commitment number) > * fees strategy like CPFP > * in-protocol announcements [0] > Good list. Another one, usually wouldn't be *protocol* as much as wallet leakage, but = could be: utxo selection algorithm (which of course may be difficult to ded= uce, but often, far from impossible). (Also trivial and increasingly irrelevant, but nVersion). With regards to coinjoin in this context (I know your points are much broad= er), my comment is: For existing protocols (joinmarket's, wasabi's, samourai's), in the equal-o= uts paradigm, I don't see much that can be done in this area. But I would ask people to consider CoinJoinXT[1] more seriously in a taproo= t/schnorr world, since it addresses this exact point. With a short (not cro= ss-block like swaps or LN setup) interaction, participants can arrange the = effect of coinjoin without the on-chain watermark of coinjoin (so, steganog= raphic). The taproot/schnorr part is needed there because multisig is requi= red from transaction to transaction in that protocol, so doing it today is = less interesting (albeit still interesting). waxwing [1] https://joinmarket.me/blog/blog/coinjoinxt/