From: Sandy Harris Subject: Re: [PATCH] CPU Jitter RNG: inclusion into kernel crypto API and /dev/random Date: Mon, 14 Oct 2013 11:46:18 -0400 Message-ID: References: <2579337.FPgJGgHYdz@tauon> <3593500.a7fOuGKlEX@tauon> <1420251.G1iR4tbUp8@tauon> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: "Theodore Ts'o" , LKML , linux-crypto@vger.kernel.org To: Stephan Mueller Return-path: Received: from mail-vc0-f173.google.com ([209.85.220.173]:56768 "EHLO mail-vc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754487Ab3JNPqT (ORCPT ); Mon, 14 Oct 2013 11:46:19 -0400 In-Reply-To: <1420251.G1iR4tbUp8@tauon> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Mon, Oct 14, 2013 at 11:26 AM, Stephan Mueller wrote: >>Why not declare some 64-bit constant C with a significant > > Which constant would you take? The CRC twist values? The SHA-1 initial > values? Or the first few from SHA-256? The only essential requirement is that it not be something stupidly regular like a 64-bit string 0x5555555555555555. I'd pick an odd number so the low bit always changes, and a constant with about half the bits set, maybe 24 < n < 40 or some such. I'm not certain either of those is strictly required but I'd do them anyway.