From owner-freebsd-hackers Sun Oct 15 22:57:59 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id WAA27008 for hackers-outgoing; Sun, 15 Oct 1995 22:57:59 -0700 Received: from grunt.grondar.za (grunt.grondar.za [196.7.18.129]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id WAA27002 for ; Sun, 15 Oct 1995 22:57:51 -0700 Received: from grumble.grondar.za (grumble.grondar.za [196.7.18.130]) by grunt.grondar.za (8.6.12/8.6.9) with ESMTP id HAA23316; Mon, 16 Oct 1995 07:57:42 +0200 Received: from localhost (localhost [127.0.0.1]) by grumble.grondar.za (8.6.12/8.6.9) with SMTP id HAA25208; Mon, 16 Oct 1995 07:57:41 +0200 Message-Id: <199510160557.HAA25208@grumble.grondar.za> X-Authentication-Warning: grumble.grondar.za: Host localhost didn't use HELO protocol To: Dave Hayes cc: hackers@freebsd.org Subject: Re: Creating a /dev/random Date: Mon, 16 Oct 1995 07:57:41 +0200 From: Mark Murray Sender: owner-hackers@freebsd.org Precedence: bulk > Mark Murray writes: > >I am building devices, /dev/random and /dev/urandom that when read give > >random noise generated in and by the kernel. > > How is this noise generated? Is it really random, by statistical > tests? It is very random, and I believe it will survive the most rigorous tests. The code maintains a pool of entropy, which is added to by system events such as interrupts, timer events eystrokes etc. As entropy is removed, the entropy count is reduced, and as events come in, this is increased. If you like, I can forward the code... > Is there any chance of having an option to take random bits from an > existing sound card if there is one there? Sure. That is a _great_ source of noise if the card is properly set up. M -- Mark Murray 46 Harvey Rd, Claremont, Cape Town 7700, South Africa +27 21 61-3768 GMT+0200 Finger mark@grumble.grondar.za for PGP key