From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WXLS5-0003nA-Kr for bitcoin-development@lists.sourceforge.net; Tue, 08 Apr 2014 02:07:53 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.174 as permitted sender) client-ip=209.85.217.174; envelope-from=gmaxwell@gmail.com; helo=mail-lb0-f174.google.com; Received: from mail-lb0-f174.google.com ([209.85.217.174]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WXLS4-0001uR-OY for bitcoin-development@lists.sourceforge.net; Tue, 08 Apr 2014 02:07:53 +0000 Received: by mail-lb0-f174.google.com with SMTP id u14so243814lbd.33 for ; Mon, 07 Apr 2014 19:07:46 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.112.137.5 with SMTP id qe5mr595004lbb.16.1396922866153; Mon, 07 Apr 2014 19:07:46 -0700 (PDT) Received: by 10.112.89.68 with HTTP; Mon, 7 Apr 2014 19:07:45 -0700 (PDT) In-Reply-To: <6669921.kYEqrMqt0u@crushinator> References: <6669921.kYEqrMqt0u@crushinator> Date: Mon, 7 Apr 2014 19:07:45 -0700 Message-ID: From: Gregory Maxwell To: Matt Whitlock Content-Type: text/plain; charset=UTF-8 X-Spam-Score: 1.1 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (gmaxwell[at]gmail.com) 1.2 RCVD_IN_BL_SPAMCOP_NET RBL: Received via a relay in bl.spamcop.net [Blocked - see ] -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 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 1.5 SF_NO_SPF_SPAM SF_NO_SPF_SPAM X-Headers-End: 1WXLS4-0001uR-OY 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 02:07:53 -0000 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.