path: root/00/a4960b7fea416b3f138f6fbfdc657d5c25e7ab

Delivery-date: Tue, 28 Jan 2025 09:36:01 -0800
Received: from mail-qv1-f57.google.com ([209.85.219.57])
	by mail.fairlystable.org with esmtps  (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
	(Exim 4.94.2)
	(envelope-from <bitcoindev+bncBD5MDHHN4EIBB5VK4S6AMGQESDVIC3Q@googlegroups.com>)
	id 1tcpVI-0002la-Rx
	for bitcoindev@gnusha.org; Tue, 28 Jan 2025 09:36:01 -0800
Received: by mail-qv1-f57.google.com with SMTP id 6a1803df08f44-6d89154adabsf96339496d6.0
        for <bitcoindev@gnusha.org>; Tue, 28 Jan 2025 09:36:00 -0800 (PST)
ARC-Seal: i=2; a=rsa-sha256; t=1738085755; cv=pass;
        d=google.com; s=arc-20240605;
        b=eOcD7X2PsSm6jFzVS1KvWi62VBNYtoquWeRVxBCQ0R+TF0CtlVzIUG/32Rg3BfGIvz
         GXpXakLkgzTh/eIomHQY7elQ/ZEd47HTMVU0eWMu1U4EKKwHBoUywcfHetYJG+8S1GHK
         hz6r90kk8wpFTEee0Yd6mgrSYwIDqUifCpKGNjflbfQyjJp6vhNvfUYJLPh3AdDf2byR
         KLw0cU+/a4t0yJJgnHItlyp7pkBxmpzL6vtU0Cv7ZeNHG3uKcMBEM7MIPZcKSF2U3HDu
         pjeFsyaemMDLiJAYC7xu5DH0WGqguW/OCvTdCulp14KZqaRqtGUj+Ahnz7biPd97Nb52
         dvMw==
ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605;
        h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post
         :list-id:mailing-list:precedence:to:subject:message-id:date:from
         :in-reply-to:references:mime-version:sender:dkim-signature;
        bh=Y6vc+sXo2wAmLyoIoBtARbF9FBDKhQ9PDzx36lM8VAU=;
        fh=0H5Y1/QKFSF505NQ7xFVGuLjGcd2NjyxaVoPGDWNAAU=;
        b=bp0cZx33oLBGedjS63fKG4V8I23yiDPseB4fEM9L2H+EeuM3UlUADYgwy9qCAXNTEY
         mWKAnim3ytsRGXP99tHXn6FPbFSqVv85p8UhHzae+xh1kXnCb8u05Fi3tGnqIOui9fsz
         tfcmuZoSo3gGj1djbqe+0ifkoErWfPYEagIg29OKZWgCa8U8Vt8A9+nXic6060+tvSPe
         ZCJj3lbJi0Zuzy19K9hboVqstH3MrsFNx4+8jzB1o3ZVxVmkDSe9Liivig8TOj4iGtB+
         bRQFe5APb8D+acVn2NcdwzuS3CcUml6CbDWkjTS/ePsClRMWTCfsFhsPQjAp6W7uCK2L
         ElGQ==;
        darn=gnusha.org
ARC-Authentication-Results: i=2; gmr-mx.google.com;
       dkim=pass header.i=@q32-com.20230601.gappssmtp.com header.s=20230601 header.b="cZ/1kx4b";
       spf=pass (google.com: domain of earonesty@gmail.com designates 2a00:1450:4864:20::629 as permitted sender) smtp.mailfrom=earonesty@gmail.com;
       dara=pass header.i=@googlegroups.com
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=googlegroups.com; s=20230601; t=1738085755; x=1738690555; darn=gnusha.org;
        h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post
         :list-id:mailing-list:precedence:x-original-authentication-results
         :x-original-sender:to:subject:message-id:date:from:in-reply-to
         :references:mime-version:sender:from:to:cc:subject:date:message-id
         :reply-to;
        bh=Y6vc+sXo2wAmLyoIoBtARbF9FBDKhQ9PDzx36lM8VAU=;
        b=L1X/YuyLLgSQOIh9QnWBKNriqmX1jJhOv0SRwLGAUWSy9+x+J5gGhnI4MGajaeSTX9
         SR7Fwd0EUGIuvnUHZjcFRV1mP1fSznJphLiR2Nt9zalUY7MNUbmRFWXhsOOIDjbdOO9P
         LYxy2e1cdKU4/xc/MKGg9I6F9m74S+IHz/vmkDSjrTEtmpXgzjH0mSJS4ZEct6sB4I/O
         0WKVJ5Stib3Zon4cxmkerNNaakaFQvXrBE6fYW6qmtbOJHX6o2V1h5RqVC+bkG2q0gpR
         0HDVJYRbJLqaYXvwMHNga+OMw/P0m+CRW4PGVyISn2F0DwfmqanC9ufJdPN/yk5eUDBr
         7F3A==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20230601; t=1738085755; x=1738690555;
        h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post
         :list-id:mailing-list:precedence:x-original-authentication-results
         :x-original-sender:to:subject:message-id:date:from:in-reply-to
         :references:mime-version:x-beenthere:x-gm-message-state:sender:from
         :to:cc:subject:date:message-id:reply-to;
        bh=Y6vc+sXo2wAmLyoIoBtARbF9FBDKhQ9PDzx36lM8VAU=;
        b=w0GHDr1fTxsfHu2rQcx7j6kKS2OUrxc/phOpq3xXUhU52ZVqND7EMaS93nuKIL4anA
         8DMV6kz4OM4XOPtuvgAxj3C5Jbh0QZRKFOtmMH1dSazJgvYEpcVBwKxYFwRBMG2sZNk+
         +iUelrKzF+DA6F5UE6UB12NT0JApLkRELVmGiCFKC+JKmY6ldxDf63XRBAXE+I+9dm5p
         JAEv7ASOnRophvlX3O+nMlGG3yuBI31gIUB6kX5aZAR6JYXW8dw3d1Fq7QmkVQeVgcot
         1av43KdP4T0Wr0g00V8XPjdsQ9iA76KGYUHtLd0hvKnF07qHosM9Q+p/mkJ+5epRjymw
         lJvQ==
Sender: bitcoindev@googlegroups.com
X-Forwarded-Encrypted: i=2; AJvYcCW8/kEXObrmS3vSL/G/CRmTbYKJmrfq2EaaC961o7/J/1X2C4KPtSsQP9Uy/ph6e5u5WPhWAd5R5tc7@gnusha.org
X-Gm-Message-State: AOJu0Yx6lz32vRF3a/U0X5dyXIl4DvnwjWpffrAveuJb1VykulpT0hLd
	pZUPdzkqqW7zJYizYzzPJuUskcr0OA+wHKSxJgue2UpqAUo2X3gD
X-Google-Smtp-Source: AGHT+IGeNshT0j21s9yTLYbovYXzPxlJu0CgfUM4FeJEQu/p9MzxkQxiJzCuBbotzMuyMkUkei4Yog==
X-Received: by 2002:a05:6214:f26:b0:6d8:ad28:adbf with SMTP id 6a1803df08f44-6e243bfaa0fmr351096d6.20.1738085753227;
        Tue, 28 Jan 2025 09:35:53 -0800 (PST)
X-BeenThere: bitcoindev@googlegroups.com
Received: by 2002:ad4:4990:0:b0:6d4:18b4:dc77 with SMTP id 6a1803df08f44-6e1fa228f7cls7468066d6.0.-pod-prod-09-us;
 Tue, 28 Jan 2025 09:35:50 -0800 (PST)
X-Forwarded-Encrypted: i=2; AJvYcCXA0pqh60szGH+ds33+rffRbR2PRXrETDMFvJhHK7OlkanILuGiZx4Rk+y2yA2Ej2kSL8dXMHMIWAKs@googlegroups.com
X-Received: by 2002:a05:620a:1902:b0:7b1:51df:117f with SMTP id af79cd13be357-7be6325c411mr7919119285a.56.1738085750192;
        Tue, 28 Jan 2025 09:35:50 -0800 (PST)
Received: by 2002:a05:620a:41:b0:7b6:d72a:7c26 with SMTP id af79cd13be357-7bff5151a18ms85a;
        Tue, 28 Jan 2025 09:34:59 -0800 (PST)
X-Forwarded-Encrypted: i=2; AJvYcCWgGeagVRCT+H/32AArp1+mWmlGVm+AkfpsSpfylcYwF3yTFqyM4IBmXmgIF0CsspTcmmCo6SeC04l6@googlegroups.com
X-Received: by 2002:ac2:41d7:0:b0:542:62e6:4517 with SMTP id 2adb3069b0e04-5439c2289d6mr12104464e87.12.1738085694730;
        Tue, 28 Jan 2025 09:34:54 -0800 (PST)
ARC-Seal: i=1; a=rsa-sha256; t=1738085694; cv=none;
        d=google.com; s=arc-20240605;
        b=cFBhM2zBasFE1XOOTGu493O95E9Hl++GXroVPNWrXrtzN6z/d009dQvkYSebvClvHi
         dug23NPMhIHRwR+7sjG587CK4ZuFknSH1wMgij/TJXRj8lVdEys0yWuBKcbMuK25EM1s
         fvHQlAsfSXVUmIs0mBqVLrST8J/Z44xqlqtDew84noF+AoSnsVTg4oKo6cK7tvXeED/w
         N8DkaAT4e11bt5Y1vGmlY2asx8pH62GwfhJ7NL17vLMmnzEQLiNThHFD38PKNqEufFTH
         nJBwL1VY+nUjyWEZPZQ6mucGJeV2BmMATt6ok9vjvNLNDguKf3RlAsAaOLLJwyQMBwsp
         kRKA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605;
        h=to:subject:message-id:date:from:in-reply-to:references:mime-version
         :dkim-signature;
        bh=fe1Y8hX5wNltjfo55y32lbJ4MExYm5CIYb1dmXn64rE=;
        fh=YQxaNPe1oCeU2DkaT20Q3NvY5ntnqbgWaZUtVoARYCk=;
        b=H/QVj9T1bPz8qaLYQzG03tlhxq4gOxmdlCsh2c/WQ3B1QqYMggUE6QWc/RV1q032dL
         KNuYbTgcu3fYryf7c61OCWc8BWU0HHORkr2MvxSbT+DEUw0GWoXNB+mv2osP38RUMzYR
         qcV//Ycaw9FQD7WGg2G4I4juKaTvuOUN6SAPYDm0DrEkbI9t//kFX8nk3fa5ZBPN3coV
         UIrrXWBLHvLckpmEARIjYO8IHiD+TvKxGoAjt2GKW+tf9stbq6w7LaCm5vv1468MzNQs
         BcOKwdII4HkBrJ7T5v6TbQL/1yw+pS1849l276CWgIV4SSlFgg/uqEtyb70pW03C3nM8
         D5Hw==;
        dara=google.com
ARC-Authentication-Results: i=1; gmr-mx.google.com;
       dkim=pass header.i=@q32-com.20230601.gappssmtp.com header.s=20230601 header.b="cZ/1kx4b";
       spf=pass (google.com: domain of earonesty@gmail.com designates 2a00:1450:4864:20::629 as permitted sender) smtp.mailfrom=earonesty@gmail.com;
       dara=pass header.i=@googlegroups.com
Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com. [2a00:1450:4864:20::629])
        by gmr-mx.google.com with ESMTPS id 2adb3069b0e04-543c82228c5si299770e87.1.2025.01.28.09.34.54
        for <bitcoindev@googlegroups.com>
        (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128);
        Tue, 28 Jan 2025 09:34:54 -0800 (PST)
Received-SPF: pass (google.com: domain of earonesty@gmail.com designates 2a00:1450:4864:20::629 as permitted sender) client-ip=2a00:1450:4864:20::629;
Received: by mail-ej1-x629.google.com with SMTP id a640c23a62f3a-aab6fa3e20eso999872166b.2
        for <bitcoindev@googlegroups.com>; Tue, 28 Jan 2025 09:34:54 -0800 (PST)
X-Forwarded-Encrypted: i=1; AJvYcCWNQMJ4t0jx1AjiItOo08c5WpDiMA3Y3Qy1GCLHlDtE0ETQazzG1eL12dPeY0lDELXByQlh7HqKPHnI@googlegroups.com
X-Gm-Gg: ASbGncuFaQ0wP1kGU2P2u/yRrGZ2ckHlRhkwYZzoG6jImwcvNVAMh0CqSiAxTS4f06W
	InXrUdeZ4sK57l1sTS0e6pzMU4uPYNqmtXmengAGNarZEgNAEcuvoc/NNTaUEqnRfD+Pj9Q2m4I
	JRfupbpuAd9cAlGYqQPKEQbO9l3CvVQNgyiNE=
X-Received: by 2002:a17:907:934a:b0:aa6:9624:78fd with SMTP id
 a640c23a62f3a-ab38b4c6436mr4348127366b.48.1738085694171; Tue, 28 Jan 2025
 09:34:54 -0800 (PST)
MIME-Version: 1.0
References: <CAJowKgJO6MbxPnyzEYYD5YxzEhPq_AkbOsmRc8a+oVMVeKC9Ew@mail.gmail.com>
 <128AF3BD-F034-46AB-B5BD-E00B405CB854@voskuil.org>
In-Reply-To: <128AF3BD-F034-46AB-B5BD-E00B405CB854@voskuil.org>
From: Erik Aronesty <erik@q32.com>
Date: Tue, 28 Jan 2025 09:34:45 -0800
X-Gm-Features: AWEUYZnhUlgrGwx_fiUHR2I4TQvqi7nDq7xiKdG6yGGRbH9MUOpKhSakxfQ-Bbw
Message-ID: <CAJowKgJypG+W8GO=n4g2Rdk2Qm4v6_hEGXA+N7meYRJaCEGpwg@mail.gmail.com>
Subject: Re: [bitcoindev] UTXO checkpoint transactions
To: Eric Voskuil <eric@voskuil.org>, bitcoindev@googlegroups.com
Content-Type: multipart/alternative; boundary="00000000000063f2fe062cc79c89"
X-Original-Sender: erik@q32.com
X-Original-Authentication-Results: gmr-mx.google.com;       dkim=pass
 header.i=@q32-com.20230601.gappssmtp.com header.s=20230601
 header.b="cZ/1kx4b";       spf=pass (google.com: domain of
 earonesty@gmail.com designates 2a00:1450:4864:20::629 as permitted sender)
 smtp.mailfrom=earonesty@gmail.com;       dara=pass header.i=@googlegroups.com
Precedence: list
Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com
List-ID: <bitcoindev.googlegroups.com>
X-Google-Group-Id: 786775582512
List-Post: <https://groups.google.com/group/bitcoindev/post>, <mailto:bitcoindev@googlegroups.com>
List-Help: <https://groups.google.com/support/>, <mailto:bitcoindev+help@googlegroups.com>
List-Archive: <https://groups.google.com/group/bitcoindev
List-Subscribe: <https://groups.google.com/group/bitcoindev/subscribe>, <mailto:bitcoindev+subscribe@googlegroups.com>
List-Unsubscribe: <mailto:googlegroups-manage+786775582512+unsubscribe@googlegroups.com>,
 <https://groups.google.com/group/bitcoindev/subscribe>
X-Spam-Score: -0.7 (/)

--00000000000063f2fe062cc79c89
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

correct, it's an "all full node vaidates" and not "trust miners only"

the intention was to *reduce* the assumption of validity hacks that i
agree, are a problem

spv should definitely be enough for mobile clients interested solely in
their own chain of wallet addresses

On Tue, Jan 28, 2025 at 9:11=E2=80=AFAM Eric Voskuil <eric@voskuil.org> wro=
te:

> More age doesn=E2=80=99t make it more valid. If you can=E2=80=99t answer =
the same
> questions that SPV can answer then use SPV. Did you mean the reverse?
>
> This constant creep toward non-validating bitcoin is troublesome, and
> largely driven by poor software performance. We have SPV (without any
> chance of fraud proofs becoming useful), =E2=80=9Cassume valid=E2=80=9D, =
and now =E2=80=9Cassume
> utxo=E2=80=9D, and people are working toward what amounts to =E2=80=9Cass=
ume utreexo=E2=80=9D. This
> cacaphony of trust-me-bro services that are drowning out individual
> validation.
>
> That aside I cannot see utxo commitments as being beneficial unless they
> are validated by full nodes (and how else would miners validate them?).
> That still reduces to SPV security, since the wallet couldn=E2=80=99t val=
idate it,
> but at least it=E2=80=99s not adding a layer of trust that miners alone w=
ill
> validate it. If you want to ensure it=E2=80=99s valid then it=E2=80=99s a=
 soft fork.
>
> e
>
> On Jan 28, 2025, at 11:52, Erik Aronesty <erik@q32.com> wrote:
>
> =EF=BB=BF
> It seems that a sufficiently aged one would be useful in situations where
> you are not able to answer the same questions that SPV can answer
>
> On Mon, Jan 27, 2025, 10:42=E2=80=AFPM Eric Voskuil <eric@voskuil.org> wr=
ote:
>
>> Hi Erik,
>>
>> Miners committing to a checkpoint does not make the checkpoint valid. Th=
e
>> only way one would know it=E2=80=99s valid is by validating the chain up=
 to that
>> point.
>>
>> Given that it implies one would be trusting hash power for validity ther=
e
>> is no need for a utxo set. SPV is sufficient. A utxo set is only necessa=
ry
>> for validation.
>>
>> e
>>
>> On Jan 28, 2025, at 01:32, Erik Aronesty <erik@q32.com> wrote:
>>
>> =EF=BB=BF
>> Has it been considered to add a UTXO checkpoint transaction
>>
>> Here's how it would work
>>
>> Someone submits a transaction that contains a large fee and a hash of th=
e
>> UTXO set along with block height as opcode parameter
>>
>> Miners refuse to include this transaction unless the hash of the UTXO se=
t
>> matches
>>
>> Because performing that hash is expensive, it should have an extremely
>> high cost factor, equivalent to say a 100KB transaction or something
>>
>> These checkpoints are explicitly for the purpose of fast-synchronizing
>> extremely lightweight nodes.  It's reasonable to refuse to use a checkpo=
int
>> that isn't at least several months old.   It should be easy for anyone t=
o
>> find a sufficiently aged checkpoint and synchronize from that point onwa=
rd.
>>
>>
>> Or is this just a solution without a problem?
>>
>>
>>
>>
>>
>>
>> --
>> You received this message because you are subscribed to the Google Group=
s
>> "Bitcoin Development Mailing List" group.
>> To unsubscribe from this group and stop receiving emails from it, send a=
n
>> email to bitcoindev+unsubscribe@googlegroups.com.
>> To view this discussion visit
>> https://groups.google.com/d/msgid/bitcoindev/CAJowKgLC9LdAu2mrQB-yW2Qoa3=
jU3BwZyL%2BQT4WW8f257Jkfhw%40mail.gmail.com
>> <https://groups.google.com/d/msgid/bitcoindev/CAJowKgLC9LdAu2mrQB-yW2Qoa=
3jU3BwZyL%2BQT4WW8f257Jkfhw%40mail.gmail.com?utm_medium=3Demail&utm_source=
=3Dfooter>
>> .
>>
>>

--=20
You received this message because you are subscribed to the Google Groups "=
Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to bitcoindev+unsubscribe@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/=
CAJowKgJypG%2BW8GO%3Dn4g2Rdk2Qm4v6_hEGXA%2BN7meYRJaCEGpwg%40mail.gmail.com.

--00000000000063f2fe062cc79c89
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div><div><div>correct, it&#39;s an &quot;all full node va=
idates&quot; and not &quot;trust miners only&quot;<br><br></div>the intenti=
on was to *reduce* the assumption of validity hacks that i agree, are a pro=
blem<br><br></div><div>spv should definitely be enough for mobile clients i=
nterested solely in their own chain of wallet addresses<br></div></div></di=
v><br><div class=3D"gmail_quote gmail_quote_container"><div dir=3D"ltr" cla=
ss=3D"gmail_attr">On Tue, Jan 28, 2025 at 9:11=E2=80=AFAM Eric Voskuil &lt;=
<a href=3D"mailto:eric@voskuil.org">eric@voskuil.org</a>&gt; wrote:<br></di=
v><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;borde=
r-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"auto"><div =
dir=3D"ltr"></div><div dir=3D"ltr">More age doesn=E2=80=99t make it more va=
lid. If you can=E2=80=99t answer the same questions that SPV can answer the=
n use SPV. Did you mean the reverse?</div><div dir=3D"ltr"><br></div><div d=
ir=3D"ltr">This constant creep toward non-validating bitcoin is troublesome=
, and largely driven by poor software performance. We have SPV (without any=
 chance of fraud proofs becoming useful), =E2=80=9Cassume valid=E2=80=9D, a=
nd now =E2=80=9Cassume utxo=E2=80=9D, and people are working toward what am=
ounts to =E2=80=9Cassume utreexo=E2=80=9D. This cacaphony of trust-me-bro s=
ervices that are drowning out individual validation.</div><div dir=3D"ltr">=
<br></div><div dir=3D"ltr">That aside I cannot see utxo commitments as bein=
g beneficial unless they are validated by full nodes (and how else would mi=
ners validate them?). That still reduces to SPV security, since the wallet =
couldn=E2=80=99t validate it, but at least it=E2=80=99s not adding a layer =
of trust that miners alone will validate it. If you want to ensure it=E2=80=
=99s valid then it=E2=80=99s a soft fork.</div><div dir=3D"ltr"><br></div><=
div dir=3D"ltr">e</div><div dir=3D"ltr"><br><blockquote type=3D"cite">On Ja=
n 28, 2025, at 11:52, Erik Aronesty &lt;<a href=3D"mailto:erik@q32.com" tar=
get=3D"_blank">erik@q32.com</a>&gt; wrote:<br><br></blockquote></div><block=
quote type=3D"cite"><div dir=3D"ltr">=EF=BB=BF<div dir=3D"auto">It seems th=
at a sufficiently aged one would be useful in situations where you are not =
able to answer the same questions that SPV can answer</div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Mon, Jan 27, 2025=
, 10:42=E2=80=AFPM Eric Voskuil &lt;<a href=3D"mailto:eric@voskuil.org" rel=
=3D"noreferrer" target=3D"_blank">eric@voskuil.org</a>&gt; wrote:<br></div>=
<blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-=
left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"auto"><div di=
r=3D"ltr"></div><div dir=3D"ltr">Hi Erik,</div><div dir=3D"ltr"><br></div><=
div dir=3D"ltr">Miners committing to a checkpoint does not make the checkpo=
int valid. The only way one would know it=E2=80=99s valid is by validating =
the chain up to that point.</div><div dir=3D"ltr"><br></div><div dir=3D"ltr=
">Given that it implies one would be trusting hash power for validity there=
 is no need for a utxo set. SPV is sufficient. A utxo set is only necessary=
 for validation.</div><div dir=3D"ltr"><br></div><div dir=3D"ltr">e</div><d=
iv dir=3D"ltr"><br><blockquote type=3D"cite">On Jan 28, 2025, at 01:32, Eri=
k Aronesty &lt;<a href=3D"mailto:erik@q32.com" rel=3D"noreferrer noreferrer=
" target=3D"_blank">erik@q32.com</a>&gt; wrote:<br><br></blockquote></div><=
blockquote type=3D"cite"><div dir=3D"ltr">=EF=BB=BF<div dir=3D"auto">Has it=
 been considered to add a UTXO checkpoint transaction=C2=A0<div dir=3D"auto=
"><br></div><div dir=3D"auto">Here&#39;s how it would work=C2=A0</div><div =
dir=3D"auto"><br></div><div dir=3D"auto">Someone submits a transaction that=
 contains a large fee and a hash of the UTXO set along with block height as=
 opcode parameter=C2=A0</div><div dir=3D"auto"><br></div><div dir=3D"auto">=
Miners refuse to include this transaction unless the hash of the UTXO set m=
atches=C2=A0</div><div dir=3D"auto"><br></div><div dir=3D"auto">Because per=
forming that hash is expensive, it should have an extremely high cost facto=
r, equivalent to say a 100KB transaction or something=C2=A0</div><div dir=
=3D"auto"><br></div><div dir=3D"auto">These checkpoints are explicitly for =
the purpose of fast-synchronizing extremely lightweight nodes.=C2=A0 It&#39=
;s reasonable to refuse to use a checkpoint that isn&#39;t at least several=
 months old.=C2=A0 =C2=A0It should be easy for anyone to find a sufficientl=
y aged checkpoint and synchronize from that point onward.</div><div dir=3D"=
auto"><br></div><div dir=3D"auto"><br></div><div dir=3D"auto">Or is this ju=
st a solution without a problem?</div><div dir=3D"auto"><br></div><div dir=
=3D"auto"><br></div><div dir=3D"auto"><br></div><div dir=3D"auto"><br></div=
><div dir=3D"auto"><br></div><div dir=3D"auto"><br></div></div>

<p></p>

-- <br>
You received this message because you are subscribed to the Google Groups &=
quot;Bitcoin Development Mailing List&quot; group.<br>
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to <a href=3D"mailto:bitcoindev+unsubscribe@googlegroups.com" rel=3D"n=
oreferrer noreferrer" target=3D"_blank">bitcoindev+unsubscribe@googlegroups=
.com</a>.<br>
To view this discussion visit <a href=3D"https://groups.google.com/d/msgid/=
bitcoindev/CAJowKgLC9LdAu2mrQB-yW2Qoa3jU3BwZyL%2BQT4WW8f257Jkfhw%40mail.gma=
il.com?utm_medium=3Demail&amp;utm_source=3Dfooter" rel=3D"noreferrer norefe=
rrer" target=3D"_blank">https://groups.google.com/d/msgid/bitcoindev/CAJowK=
gLC9LdAu2mrQB-yW2Qoa3jU3BwZyL%2BQT4WW8f257Jkfhw%40mail.gmail.com</a>.<br>
</div></blockquote></div></blockquote></div>
</div></blockquote></div></blockquote></div>

<p></p>

-- <br />
You received this message because you are subscribed to the Google Groups &=
quot;Bitcoin Development Mailing List&quot; group.<br />
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to <a href=3D"mailto:bitcoindev+unsubscribe@googlegroups.com">bitcoind=
ev+unsubscribe@googlegroups.com</a>.<br />
To view this discussion visit <a href=3D"https://groups.google.com/d/msgid/=
bitcoindev/CAJowKgJypG%2BW8GO%3Dn4g2Rdk2Qm4v6_hEGXA%2BN7meYRJaCEGpwg%40mail=
.gmail.com?utm_medium=3Demail&utm_source=3Dfooter">https://groups.google.co=
m/d/msgid/bitcoindev/CAJowKgJypG%2BW8GO%3Dn4g2Rdk2Qm4v6_hEGXA%2BN7meYRJaCEG=
pwg%40mail.gmail.com</a>.<br />

--00000000000063f2fe062cc79c89--