From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 54CE2C07FF for ; 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 ; 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 ; 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 ; Tue, 31 Mar 2020 10:36:33 +0000 (UTC) Received: from harding by newmail.dtrt.org with local (Exim 4.92) (envelope-from ) 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" To: Tom Trevethan , Bitcoin Protocol Discussion Message-ID: <20200331103508.asvxujkhtifj6n7i@ganymede> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="6oelcg7ybyojdonb" Content-Disposition: inline In-Reply-To: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-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----- iQIzBAEBCgAdFiEEgxUkqkMp0LnoXjCr2dtBqWwiadMFAl6DHNwACgkQ2dtBqWwi adNMgQ/7BZ6kSuVuPPzJ35gnEz/Kc55cAWBlkLWTyNF0DORATkYKcPPMMjTmkMlg 6Yz1vZCUt/pBC8wK4iH590uBXHO45G0+/Eq9FSykfFTpccv3ZzEuaU6QoTtHuq+5 7pgV80t2d469h1rqbVYDbcko8e87zjohnwUrwSy/KTEkZiCehjxxRuOedIBAuvZg 6pDuiAam+rJsg/Lb/6VikS+JF1aqC6x55G/A3zSfVi4ZkhhM7s/c7Nw6SzsxdKNf Vc7pNUWepoHbiT9jiDqwj7dvkV7JJMhy8owM7An7wsKA6FDXHsICrEif4KHm7+hZ 47AWUw+FiDrMLyGJdQFdYlj1Xab5Q/5O/xP9k6KWOYg6R4UtGT2AqGPcfuYjMkyG H0o41jq9lb9mTt2ydRd59ZNEKT58umkMpS2jjDWy5o1CWE2UZvWIpWqvs8wXx3He GGC4+4M9sK8MDCfmLLGBtMWqQdHdCFgTzj3O6Z1Hm4kKpZHRws4X/YaYsd8EZoCC M3d/0T7S15qtmqDtHM3eoJbONmSSHEWOVZ/EfPqoJNjOIjaOhWLd8AL5t06Iywop 87Q0SAuYyYu2sQ5AJscc4oZ3rYVRckgXKHtEpImSfGrbTSBjw1qdMxBEnKpJTmx7 bfAQfTWdtStWiNt5o2GWXKPdq3Bg5DAMbWLUTJnmg+SCf5S22aw= =U0Ka -----END PGP SIGNATURE----- --6oelcg7ybyojdonb--