1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
Return-Path: <dave@dtrt.org>
Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137])
by lists.linuxfoundation.org (Postfix) with ESMTP id 54CE2C07FF
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 31 Mar 2020 10:36:34 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
by fraxinus.osuosl.org (Postfix) with ESMTP id 4E5DD85F83
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 31 Mar 2020 10:36:34 +0000 (UTC)
X-Virus-Scanned: amavisd-new at osuosl.org
Received: from fraxinus.osuosl.org ([127.0.0.1])
by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)
with ESMTP id xqwOMH96n5Xy
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 31 Mar 2020 10:36:33 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from newmail.dtrt.org (li1228-87.members.linode.com [45.79.129.87])
by fraxinus.osuosl.org (Postfix) with ESMTPS id 93F4C85F6C
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 31 Mar 2020 10:36:33 +0000 (UTC)
Received: from harding by newmail.dtrt.org with local (Exim 4.92)
(envelope-from <dave@dtrt.org>)
id 1jJEFz-0003hM-Pf; Tue, 31 Mar 2020 06:36:31 -0400
Date: Tue, 31 Mar 2020 06:35:08 -0400
From: "David A. Harding" <dave@dtrt.org>
To: Tom Trevethan <tom@commerceblock.com>,
Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Message-ID: <20200331103508.asvxujkhtifj6n7i@ganymede>
References: <CAJvkSseW9OZ50yQiS7e0zt9tQt4v9aoikgGs_54_kMN-ORkQgw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
protocol="application/pgp-signature"; boundary="6oelcg7ybyojdonb"
Content-Disposition: inline
In-Reply-To: <CAJvkSseW9OZ50yQiS7e0zt9tQt4v9aoikgGs_54_kMN-ORkQgw@mail.gmail.com>
User-Agent: NeoMutt/20180716
Subject: Re: [bitcoin-dev] Statechain implementations
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>,
<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/>
List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org>
List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>,
<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe>
X-List-Received-Date: Tue, 31 Mar 2020 10:36:34 -0000
--6oelcg7ybyojdonb
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Wed, Mar 25, 2020 at 01:52:10PM +0000, Tom Trevethan via bitcoin-dev wro=
te:
> Hi all,
>=20
> We are starting to work on an implementation of the statechains concept (
> https://medium.com/@RubenSomsen/statechains-non-custodial-off-chain-bitco=
in-transfer-1ae4845a4a39),
>
> [...]
> There are two main modifications we are looking at:
> [...]
>=20
> 2. Replacing the 2-of-2 multisig output (paying to statechain entity SE k=
ey
> and transitory key) with a single P2(W)PKH output where the public key
> shared between the SE and the current owner. The SE and the current owner
> can then sign with a 2-of-2 ECDSA MPC.=20
Dr. Trevethan,
Would you be able to explain how your proposal to use statechains with
2P-ECDSA relates to your patent assigned to nChain Holdings for "Secure
off-chain blockchain transactions"?[1] =20
[1] https://patents.google.com/patent/US20200074464A1
Here are some excerpts from the application that caught my attention in
the context of statechains in general and your proposal to this list in
particular:
> an exchange platform that is trusted to implement and operate the
> transaction protocol, without requiring an on-chain transaction. The
> off-chain transactions enable one computer system to generate multiple
> transactions that are recordable to a blockchain in different
> circumstances
>
> [...]
>
> at least some of the off-chain transactions are valid for recording on
> the blockchain even in the event of a catastrophic failure of the
> exchange (e.g., exchange going permanently off-line or loosing key
> shares).
>
> [...]
>
> there may be provided a computer readable storage medium including a
> two-party elliptic curve digital signature algorithm (two-party ECDSA)
> script comprising computer executable instructions which, when
> executed, configure a processor to perform functions of a two-party
> elliptic curve digital signature algorithm described herein.
>
> [...]
>
> In this instance the malicious actor would then also have to collude
> with a previous owner of the funds to recreate the full key. Because
> an attack requires either the simultaneous theft of both exchange and
> depositor keys or collusion with previous legitimate owners of funds,
> the opportunities for a malicious attacker to compromise the exchange
> platform are limited.
Thank you,
-Dave
--6oelcg7ybyojdonb
Content-Type: application/pgp-signature; name="signature.asc"
-----BEGIN PGP SIGNATURE-----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=U0Ka
-----END PGP SIGNATURE-----
--6oelcg7ybyojdonb--
|
