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From: Cameron Garnham <da2ce7@gmail.com>
In-Reply-To: <CAAS2fgRGbnH-NtPRdLe0yhFSoqJ7b6O25LfyGv_ULHhy8bBSpg@mail.gmail.com>
Date: Wed, 29 Jun 2016 00:40:23 +0300
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References: <87h9cecad5.fsf@rustcorp.com.au>
	<1E86A00F-0609-4DBC-9543-94AE04CC13C9@voskuil.org>
	<577234A4.3030808@jonasschnelli.ch>
	<360EF9B8-A174-41CA-AFDD-2BC2C0B4DECB@voskuil.org>
	<20160628182202.GA5519@fedora-21-dvm>
	<D40F9E9D-DB6C-4083-A9E8-C5EBC363DB30@voskuil.org>
	<20160628201447.GA1148@fedora-21-dvm>
	<4DCF7DD2-6533-4F79-8CA1-871B67C01BDA@voskuil.org>
	<20160628203605.GA1328@fedora-21-dvm>
	<E8335291-7142-4E21-A1E2-76F387426741@voskuil.org>
	<CAAS2fgRGbnH-NtPRdLe0yhFSoqJ7b6O25LfyGv_ULHhy8bBSpg@mail.gmail.com>
To: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP 151
Precedence: list


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Unauthenticated link level encryption is wonderful! MITM attacks are overrat=
ed; as they require an active attacker.

Stopping passive attacks is the low hanging fruit. This should be taken firs=
t.

Automated and secure peer authentication in a mesh network is a huge topic. O=
ne of the unsolved problems in computer science.

A simple 'who is that' by asking for the fingerprint of your peers from your=
 other peers is a very simple way to get 'some' authentication.  Semi-truste=
d index nodes also is a low hanging fruit for authentication.

However, let's first get unauthenticated encryption. Force the attackers to u=
se active attacks. (That are thousands times more costly to couduct).

Sent from my iPhone

> On 29 Jun 2016, at 00:36, Gregory Maxwell via bitcoin-dev <bitcoin-dev@lis=
ts.linuxfoundation.org> wrote:
>=20
> On Tue, Jun 28, 2016 at 9:22 PM, Eric Voskuil via bitcoin-dev
> <bitcoin-dev@lists.linuxfoundation.org> wrote:
>> An "out of band key check" is not part of BIP151.
>=20
> It has a session ID for this purpose.
>=20
>> It requires a secure channel and is authentication. So BIP151 doesn't pro=
vide the tools to detect an attack, that requires authentication. A general r=
equirement for authentication is the issue I have raised.
>=20
> One might wonder how you ever use a Bitcoin address, or even why we
> might guess these emails from "you" aren't actually coming from the
> NSA.
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><div><span style=3D"background-color: rgba(=
255, 255, 255, 0);">Unauthenticated link level encryption is wonderful! MITM=
 attacks are overrated; as they require an active attacker.</span><div><span=
 style=3D"background-color: rgba(255, 255, 255, 0);"><br></span></div><div><=
span style=3D"background-color: rgba(255, 255, 255, 0);">Stopping passive at=
tacks is the low hanging fruit. This should be taken first.</span></div><div=
><span style=3D"background-color: rgba(255, 255, 255, 0);"><br></span></div>=
<div><span style=3D"background-color: rgba(255, 255, 255, 0);">Automated and=
 secure peer authentication in a mesh network is a huge topic. One of the un=
solved problems in computer science.</span></div><div><span style=3D"backgro=
und-color: rgba(255, 255, 255, 0);"><br></span><div><div><span style=3D"back=
ground-color: rgba(255, 255, 255, 0);">A simple 'who is that' by&nbsp;asking=
 for the fingerprint of your peers from your other peers is a very simple wa=
y to get 'some' authentication. &nbsp;Semi-trusted index nodes also is a low=
 hanging fruit for authentication.</span></div><div><span style=3D"backgroun=
d-color: rgba(255, 255, 255, 0);"><br></span></div><span style=3D"background=
-color: rgba(255, 255, 255, 0);">However, let's first get u<font>nauthentica=
ted encryption. Force the attackers to use active attacks. (That are thousan=
ds times more costly to couduct).</font></span></div></div><br>Sent from my i=
Phone</div><div><br>On 29 Jun 2016, at 00:36, Gregory Maxwell via bitcoin-de=
v &lt;<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@l=
ists.linuxfoundation.org</a>&gt; wrote:<br><br></div><blockquote type=3D"cit=
e"><div><span>On Tue, Jun 28, 2016 at 9:22 PM, Eric Voskuil via bitcoin-dev<=
/span><br><span>&lt;<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org"=
>bitcoin-dev@lists.linuxfoundation.org</a>&gt; wrote:</span><br><blockquote t=
ype=3D"cite"><span>An "out of band key check" is not part of BIP151.</span><=
br></blockquote><span></span><br><span>It has a session ID for this purpose.=
</span><br><span></span><br><blockquote type=3D"cite"><span>It requires a se=
cure channel and is authentication. So BIP151 doesn't provide the tools to d=
etect an attack, that requires authentication. A general requirement for aut=
hentication is the issue I have raised.</span><br></blockquote><span></span>=
<br><span>One might wonder how you ever use a Bitcoin address, or even why w=
e</span><br><span>might guess these emails from "you" aren't actually coming=
 from the</span><br><span>NSA.</span><br><span>_____________________________=
__________________</span><br><span>bitcoin-dev mailing list</span><br><span>=
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.l=
inuxfoundation.org</a></span><br><span><a href=3D"https://lists.linuxfoundat=
ion.org/mailman/listinfo/bitcoin-dev">https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev</a></span><br></div></blockquote></body></html>=

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