Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WcVo5-0002Gv-Cf for bitcoin-development@lists.sourceforge.net; Tue, 22 Apr 2014 08:11:57 +0000 X-ACL-Warn: Received: from qmta03.westchester.pa.mail.comcast.net ([76.96.62.32]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1WcVo3-0002KN-If for bitcoin-development@lists.sourceforge.net; Tue, 22 Apr 2014 08:11:57 +0000 Received: from omta11.westchester.pa.mail.comcast.net ([76.96.62.36]) by qmta03.westchester.pa.mail.comcast.net with comcast id swAa1n0020mv7h053wBqbT; Tue, 22 Apr 2014 08:11:50 +0000 Received: from crushinator.localnet ([IPv6:2601:6:4800:47f:219:d1ff:fe75:dc2f]) by omta11.westchester.pa.mail.comcast.net with comcast id swBo1n00S4VnV2P3XwBpn7; Tue, 22 Apr 2014 08:11:49 +0000 From: Matt Whitlock To: jan.moller@gmail.com, bitcoin-development Date: Tue, 22 Apr 2014 04:11:48 -0400 Message-ID: <1927948.OEZHQcsQ9n@crushinator> User-Agent: KMail/4.13 (Linux/3.12.13-gentoo; KDE/4.13.0; x86_64; ; ) In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" X-Spam-Score: 0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [76.96.62.32 listed in list.dnswl.org] 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1WcVo3-0002KN-If Subject: Re: [Bitcoin-development] Presenting a BIP for Shamir's Secret Sharing of Bitcoin private keys X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Apr 2014 08:11:57 -0000 On Tuesday, 22 April 2014, at 10:06 am, Jan M=F8ller wrote: > This is a very useful BIP, and I am very much looking forward to > implementing it in Mycelium, in particular for bip32 wallets. > To me this is not about whether to use SSS instead of multisig > transactions. In the end you want to protect a secret (be it a HD mas= ter > seed or a private key) in such a way that you can recover it in case = of > partial theft/loss. Whether I'll use the master seed to generate keys= that > are going to be used for multisig transactions is another discussion = IMO. >=20 > A few suggestions: > - I think it is very useful to define different prefixes for testnet= > keys/seeds. As a developer I use the testnet every day, and many of o= ur > users use it for trying out new functionality. Mixing up keys meant f= or > testnet and mainnet is bad. A fair point. I'll add some prefixes for testnet. > - Please allow M=3D1. From a usability point of view it makes sense = to allow > the user to select 1 share if that is what he wants. How does that make sense? Decomposing a key/seed into 1 share is functi= onally equivalent to dispensing with the secret sharing scheme entirely= . > I have no strong opinions of whether to use GF(2^8) over Shamir's Sec= ret > Sharing, but the simplicity of GF(2^8) is appealing. I'll welcome forks of my draft BIP. I don't really have the inclination= to research GF(2^8) secret sharing schemes and write an implementation= at the present time, but if someone wants to take my BIP in that direc= tion, then okay.