From owner-freebsd-numerics@FreeBSD.ORG Tue Mar 17 21:24:57 2015 Return-Path: Delivered-To: freebsd-numerics@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 52467BB7 for ; Tue, 17 Mar 2015 21:24:57 +0000 (UTC) Received: from nm38-vm4.bullet.mail.bf1.yahoo.com (nm38-vm4.bullet.mail.bf1.yahoo.com [72.30.239.20]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id EC12BE2A for ; Tue, 17 Mar 2015 21:24:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1426627315; bh=SUmQ2y2fFfP7jKCcEqv6DdZ6Aaq9Te7Pff5XcfAfzc4=; h=Date:From:To:CC:Subject:References:In-Reply-To:From:Subject; b=aE3WGKU8j9xR1fSZA0d7kkfhwcWMRlWRj2kaHVHRF7TEhI+pFD8S2mVg2XZ6g+LNlc/+wWxuuPV8Kj2pXbSbC0sXLWlY8Nz/d4hi2XKqc/gXxSX05S0nHH8WVg/j4tJPJ00+MZuwBHLR8B/o6XFq/WskF4ryp6mzd0JJ00vpWxurM562ipk729m2+QVLUnFMrCKvcA+X+8UtILtr1pCfB/4ffFBc9ZZu5dYtnzsZIpJ+d54bmKn5yWfn3bYN0voiykCeVinbqivb921uD2QJeQHjOH6oNXNDdWiYrUXyrIS6+QzUJl3J11l0RY6WL7GEoWgzzMSV9Y/vR2NKMnfc/A== Received: from [98.139.215.143] by nm38.bullet.mail.bf1.yahoo.com with NNFMP; 17 Mar 2015 21:21:55 -0000 Received: from [98.139.211.207] by tm14.bullet.mail.bf1.yahoo.com with NNFMP; 17 Mar 2015 21:21:55 -0000 Received: from [127.0.0.1] by smtp216.mail.bf1.yahoo.com with NNFMP; 17 Mar 2015 21:21:55 -0000 X-Yahoo-Newman-Id: 927753.93401.bm@smtp216.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: S_068A0VM1lLok2HufVfazH1LFmlBVpv86tVlMVm6mCSk6o KXLco6yqoQoPPKGM5RwHbFV81eSFUnAXvtEPjKwSa1zPongsHbFkPgKGG0Rt wgyLNg5BT0lgE7fzLEi9tytvGWbga1JYjt9U8as5H6THj2_HDV0awQAgl.5T rRqZMo0XjScR7aP9rxqhETkuJLHNHcY3nx1SJLCBnH3XNZfukuKXnlanFADH 0COxI7F0Za6l.5eBMevh0ypQwMA3i.yBi_p5rlrYzlRl933OZFd5_yy8mfwy JEMDWpJBDpvFgq5GIHYW_Ht.54VoVORDOWp_CQCYn7AifiuPdGZ83ZgUU3T4 8HPhKRuefG_aqqtP14VD4e7jQD0YYzlXwuOMT3GYsy8bxLeBd.F0celGrCDh bpTOFsjkVtdeZMpoNgPgFMtny1q7XfhLCk4BMrDeUUt6N_0ezRLs5vzCNvol wWd6j05O5dlrGYZQkbDLtpr6h3IPJh3SUd20LsxeRwrp2cNoirVlMpAiVF0m Z2sDUUCCoK8CpQM82Fd2VEjF7F0h3wu3W X-Yahoo-SMTP: xcjD0guswBAZaPPIbxpWwLcp9Unf Message-ID: <55089B08.4020501@FreeBSD.org> Date: Tue, 17 Mar 2015 16:22:16 -0500 From: Pedro Giffuni User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Steve Kargl , "Dennis E. Hamilton" Subject: Re: Random number generators References: <7CBD7758-9472-4A2E-8065-EC6E68EE8DAB@FreeBSD.org> <20150317060310.GA21975@troutmask.apl.washington.edu> <00a001d060d7$0077f100$0167d300$@acm.org> <20150317184618.GA24951@troutmask.apl.washington.edu> In-Reply-To: <20150317184618.GA24951@troutmask.apl.washington.edu> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-numerics@FreeBSD.org X-BeenThere: freebsd-numerics@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Discussions of high quality implementation of libm functions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Mar 2015 21:24:57 -0000 On 03/17/15 13:46, Steve Kargl wrote: > On Tue, Mar 17, 2015 at 10:22:51AM -0700, Dennis E. Hamilton wrote: >> If you are serious about crypto grade randomness, libc is probably >> not the answer. Generally, I don't think reliance on a single >> generator for general purpose use and for cryptographic quality >> is going to work well. This is a very context-sensitive situation >> and addressing specific threat models against cryptographic PRGs >> is a very different matter from wanting unpredictable and good >> quality pseudo-randoms for simulations and other purposes. >> > I intrepeted Pedro's original email to mean something better > than rand(3) and random(3). You interpreted right. Unfortunately I don't see us changing the POSIX behavior in libc (specially not in the brutal way OpenBSD did), and even if we were to change it, we would still have to carry the old version for compatibility through symbol versioning so the only choice for interested parties is to add their own implementation, and live with the bloat of existing versions. It was really nice to learn about kiss() though. Pedro.