From: xor <xor@freenetproject.org>
To: bitcoin-development@lists.sourceforge.net
Date: Thu, 07 Aug 2014 15:00:11 +0200
Message-ID: <1530801.palqu9XdN4@1337h4x0r>
Organization: Freenet Project
User-Agent: KMail/4.13.2 (Linux/3.13.0-32-generic; KDE/4.13.2; x86_64; ; )
In-Reply-To: <8137823.B0x87S28xY@calzone>
References: <8137823.B0x87S28xY@calzone>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="nextPart20408252.l0l1QHbILQ";
	micalg="pgp-sha256"; protocol="application/pgp-signature"
Subject: Re: [Bitcoin-development] CoinShuffle: decentralized CoinJoin
	without trusted third parties
Precedence: list
Reply-To: xor@freenetproject.org


--nextPart20408252.l0l1QHbILQ
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="us-ascii"

On Thursday, August 07, 2014 12:22:31 AM Tim Ruffing wrote:
>  - Decentralization / no third party:
> There is no (trusted or untrusted) third party in a run of the protoc=
ol.
> (Still, as in all mixing solutions, users need some way to gather tog=
ether
> before they can run the protocol. This can be done via a P2P protocol=
 if a
> decentralized solution is desired also for this step.)
[...]
> http://crypsys.mmci.uni-saarland.de/projects/CoinShuffle/ for a techn=
ical
> overview.=20

I think the description at your website leaves out the truly interestin=
g part:
How do you decentralize this securely?
=2D How do Alice, Bob, Charlie and Dave communicate, i.e. which network i=
s used=20
for communication and how?
=2D How does Alice know that Bob, Charlie and Dave are not the same perso=
n?
(=3D how do you prevent a Sybil attack?)

Because thats the real problem with mixing it seems - ensuring that you=
r=20
mixing partners are actually 100 people and not just 1 attacker. There =
are=20
probably many mixing algorithms which work if you solve that problem, b=
ut I=20
don't see how you offer a solution for it :(
--nextPart20408252.l0l1QHbILQ
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: This is a digitally signed message part.
Content-Transfer-Encoding: 7Bit

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
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=5oUV
-----END PGP SIGNATURE-----

--nextPart20408252.l0l1QHbILQ--