Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WXUaA-0005uf-3Q for bitcoin-development@lists.sourceforge.net; Tue, 08 Apr 2014 11:52:50 +0000 X-ACL-Warn: Received: from qmta14.westchester.pa.mail.comcast.net ([76.96.59.212]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1WXUa8-0007Q6-Ta for bitcoin-development@lists.sourceforge.net; Tue, 08 Apr 2014 11:52:50 +0000 Received: from omta14.westchester.pa.mail.comcast.net ([76.96.62.60]) by qmta14.westchester.pa.mail.comcast.net with comcast id nPcJ1n0041HzFnQ5EPsjBJ; Tue, 08 Apr 2014 11:52:43 +0000 Received: from crushinator.localnet ([IPv6:2601:6:4800:47f:219:d1ff:fe75:dc2f]) by omta14.westchester.pa.mail.comcast.net with comcast id nPsi1n0084VnV2P3aPsjt3; Tue, 08 Apr 2014 11:52:43 +0000 From: Matt Whitlock To: Gregory Maxwell Date: Tue, 08 Apr 2014 07:52:41 -0400 Message-ID: <16848732.PiyLLsBBZa@crushinator> User-Agent: KMail/4.12.4 (Linux/3.12.13-gentoo; KDE/4.12.4; x86_64; ; ) In-Reply-To: References: <6669921.kYEqrMqt0u@crushinator> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: Matt Whitlock 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 [76.96.59.212 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: 1WXUa8-0007Q6-Ta Cc: bitcoin-development 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, 08 Apr 2014 11:52:50 -0000 On Monday, 7 April 2014, at 7:07 pm, Gregory Maxwell wrote: > On Mon, Apr 7, 2014 at 6:46 PM, Matt Whitlock wrote: > > On Monday, 7 April 2014, at 5:38 pm, Gregory Maxwell wrote: > >> On Mon, Apr 7, 2014 at 5:33 PM, Nikita Schmidt > >> wrote: > >> > Regarding the choice of fields, any implementation of this BIP will > >> > need big integer arithmetic to do base-58 anyway. > >> Nah, it doesn't. E.g. > >> https://gitorious.org/bitcoin/libblkmaker/source/eb33f9c8e441ffef457a79d76ceed1ea20ab3059:base58.c > > That only *decodes* Base58Check. It has no encode function, which would require biginteger division. > > Yes thats only a decode but the same process (long division with > manual carries) works just fine the other way. There is absolutely no > need to use big integers for this. What do you think a big-integer division by a word-sized divisor *is*? Obviously rolling your own is always an option. Are you just saying that Base58 encoding and decoding is easier than Shamir's Secret Sharing because the divisors are small?