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 72161C002D for ; Sat, 1 Oct 2022 10:19:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 3987A4177C for ; Sat, 1 Oct 2022 10:19:04 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 3987A4177C Authentication-Results: smtp4.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=lvjipETd X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.098 X-Spam-Level: X-Spam-Status: No, score=-2.098 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, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=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 w1mjilnWl97S for ; Sat, 1 Oct 2022 10:19:02 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 5FDA041778 Received: from mail-oa1-x30.google.com (mail-oa1-x30.google.com [IPv6:2001:4860:4864:20::30]) by smtp4.osuosl.org (Postfix) with ESMTPS id 5FDA041778 for ; Sat, 1 Oct 2022 10:19:02 +0000 (UTC) Received: by mail-oa1-x30.google.com with SMTP id 586e51a60fabf-131ea99262dso5859744fac.9 for ; Sat, 01 Oct 2022 03:19:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date; bh=XiG4DW2bCp4Had49V/6BC4eRK2lHadr4hvFOycG2L1I=; b=lvjipETdkUxwYJQHrWlelsjWg03p9pBu8gCIul55saQ3bh+ELGvsz/tNmixFJ8rCmh T20pVFAvjp+3w9XiKNXSMFzcw5F098cjw/gizhYPYZh4e+z2J/r/fRqce4cx/41ewloo H/nxD5iACmqiCLO2wW3OzXRpWjzTvspkqNLAQ0CwAYJtlZJS9X6tBAyA7Qgl7ybHskFW XNylNl1+/P1CcnpZFip7b8FHEpzz9gz2kQWpOlShcPoSDh1rL0ME00pDRgf7ZEkQSL33 yVjY+0q1WD+G5sT3HoOZOCQx746yqiNvQ3SBVSmUHLRT/RJl/tK3/23fYW2Iurbi69tr QJ1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=XiG4DW2bCp4Had49V/6BC4eRK2lHadr4hvFOycG2L1I=; b=oA/AbEJ8KqN5HhYiWRmC9O8siKjsFH36ZWxnnnDs5WRXU5dJ3Bc4PDLAaPn0nO4rUm VOOAljTdO9MPyevJB//Cty9DCaC1BheRNWVeRQCJwql9CYFiObCI3hjDlOeCSRmGeSQa oCFLEamuY7z7pULXY/6r+/5xyfrZq+k1ehAcp8DVDqBcUIwoEwzbVUTbWgfv3xHkLo/b onDMXEI1hAywAvKxk8xN3vaOFcBe+iM3vDZ4aBKcfBqaQKSmP/bxkN2Qb17HtoXJ+i8W X1J0U/CiDB0x+D4/BkO8aqJ7+RyfVerQhoUKLkftGUFBqZ97/ImuNh6X3gk/3YqIrtuN hVYg== X-Gm-Message-State: ACrzQf006cKlYULrT8aHsrhXO5XskclGuzK+yh96tvoDzaQkXprgQx1h PIqYnTtuAHgxcYPfmoecUaajKxzQu8H8P/9JcOQ= X-Google-Smtp-Source: AMsMyM7D8PmgRdme+YOzMn8fOlH3Ag0Ytnf3ZXg22A6isTMMo4aGC1irtdxbO0KArSM7bOtBcEZKfCthe1NIH2CP4Wk= X-Received: by 2002:a05:6870:c0c9:b0:127:c4df:5b50 with SMTP id e9-20020a056870c0c900b00127c4df5b50mr1082882oad.126.1664619541353; Sat, 01 Oct 2022 03:19:01 -0700 (PDT) MIME-Version: 1.0 References: <6xXKU-w7H59G0i0KInVVRYJWX5hPvs-5NUrsHeUEKQRWpzRxrWa4qxq4M3Hq6dcW00ps2lWdMejDtMj7640LXNTqQ3UK6j06U0-nuvOYhrA=@pointbiz.com> In-Reply-To: <6xXKU-w7H59G0i0KInVVRYJWX5hPvs-5NUrsHeUEKQRWpzRxrWa4qxq4M3Hq6dcW00ps2lWdMejDtMj7640LXNTqQ3UK6j06U0-nuvOYhrA=@pointbiz.com> From: Ruben Somsen Date: Sat, 1 Oct 2022 12:18:49 +0200 Message-ID: To: Peter Content-Type: multipart/alternative; boundary="00000000000072d7c105e9f670ae" X-Mailman-Approved-At: Sat, 01 Oct 2022 10:19:24 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Trustless Address Server ? Outsourcing handing out addresses 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, 01 Oct 2022 10:19:04 -0000 --00000000000072d7c105e9f670ae Content-Type: text/plain; charset="UTF-8" Hi Peter, Thanks for your comments. >handing out xpubs makes the gap limit problem quadratic Yes, my thinking on this is that if you're handing out xpubs you can lower the gap limit for addresses generated by those xpubs, provided you assume those addresses will be used by the same person, so there is less of a reason to expect a gap. This thread is related: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-September/020954.html >How can we make a layer 1 address that expires This was brought up by Sjors Provoost in relation to Silent Payments. He suggested embedding a sunset date in the address format. >Could there be some more exotic deterministic path that doesn't split receive and change addresses I don't follow this one. I see no reason not to split the two, and I do see potential pitfalls when you don't. Conceptually, I think receiving money twice on the same address is never good. Even if you're doing it to actively mislead people, that attempt is still leaking information that simply didn't need to be leaked. Cheers, Ruben On Sat, Oct 1, 2022 at 10:57 AM Peter via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > Hi Ruben, > > > I think this is an important conversation you have raised. I want to add > some points for discussion. > > > 1) handing out xpubs makes the gap limit problem quadratic. > > > Each customer, of a given business, on an invoice must be given a unique > address or xpub but they may pay in cash or credit card or bank wire. How > do we present more than 20 customers with an "invoice address" (regular > address or xpub)? > > (In Lightning world you give a Lightning address that uses plus addresses. > Like castiron+customer1.invoice1@LSP.com > > > If you hand out xpubs it can be the case that you hand out a consecutive > streak of 20 xpubs that are never used. Your wallet has to scan 20 xpubs > and their 20 first receive addresses. > > > > 2) Whether you give the sender an address for reuse or an xpub for reuse > there needs to be an expiry such that the receiver can confirm they still > have the corresponding keys. How can we make a layer 1 address that expires > like a PGP key where it can still be used but raises a warning to the > sender? > > (In Lightning we have that) > > > 3) Could there be some more exotic deterministic path that doesn't split > receive and change addresses? What is the first principle of splitting > change and receive? What's wrong with an address reused exactly twice? The > sender and receiver both with know what was a payment and what was change. > Will it create plausible deniability about change addresses? > > > Satoshi original wallet concept was an ever growing key pool with a 100 > address "gap". Maybe the solution to the gap limit is to add invoice > functionality to wallets that manage issuing fresh addresses even without > them being used and have a configurable gap limit. Is that what > Btcpayserver does? > > > Regards > > Peter Kroll > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > --00000000000072d7c105e9f670ae Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Peter,

Thanks for your comments.
=

>handing out xpubs makes the gap limit problem quadr= atic

Yes, my thinking on this is that if you'r= e handing out xpubs you can lower the gap limit for addresses generated by = those xpubs, provided you assume those addresses will be used by the same p= erson, so there is less of a reason to expect a gap. This thread is related= :

&g= t;How can we make a layer 1 address that expires

T= his was brought up by Sjors Provoost in relation to Silent Payments. He sug= gested embedding a sunset date in the address format.

<= div>>Could there be some more exotic deterministic path that doesn't= split receive and change addresses

I don't fo= llow this one. I see no reason not to split the two, and I do see potential= pitfalls when you don't. Conceptually, I think receiving money twice o= n the same address is never good. Even if you're doing it to actively m= islead people, that attempt is still leaking information that simply didn&#= 39;t need to be leaked.

Cheers,
Ruben

On Sat, Oct 1, 2022 at 10:57 AM Peter via bitcoin-dev <bitcoin-dev@lists.linuxfo= undation.org> wrote:
Hi Ruben,


I think this is an impor= tant conversation you have raised. I want to add some points for discussion= .


1) handing out xpubs makes the gap limit pr= oblem quadratic.


Each customer, of a given bu= siness, on an invoice must be given a unique address or xpub but they may p= ay in cash or credit card or bank wire. How do we present more than 20 cust= omers with an "invoice address" (regular address or xpub)?
(In Lightning world you give a Lightning address that uses plus add= resses. Like castiron+customer1.invoice1@LSP.com


If you hand out xpubs it can be the case that you hand out a consecutive= streak of 20 xpubs that are never used. Your wallet has to scan 20 xpubs a= nd their 20 first receive addresses.


2) Whether you give the sender an address for reuse or an xpub for r= euse there needs to be an expiry such that the receiver can confirm they st= ill have the corresponding keys. How can we make a layer 1 address that exp= ires like a PGP key where it can still be used but raises a warning to the = sender?

(In Lightning we have that)


3) Could there be some more exotic deterministic path that doesn't = split receive and change addresses? What is the first principle of splittin= g change and receive? What's wrong with an address reused exactly twice= ? The sender and receiver both with know what was a payment and what was ch= ange. Will it create plausible deniability about change addresses?

Satoshi original wallet concept was an ever growing k= ey pool with a 100 address "gap". Maybe the solution to the gap l= imit is to add invoice functionality to wallets that manage issuing fresh a= ddresses even without them being used and have a configurable gap limit. Is= that what Btcpayserver does?


Regards
Peter Kroll

________________________________________= _______
bitcoin-dev mailing list
= bitcoin-dev@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mail= man/listinfo/bitcoin-dev
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