Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964793Ab2J3Oz1 (ORCPT ); Tue, 30 Oct 2012 10:55:27 -0400 Received: from mta-out.inet.fi ([195.156.147.13]:54829 "EHLO kirsi1.inet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932633Ab2J3OzZ (ORCPT ); Tue, 30 Oct 2012 10:55:25 -0400 Message-ID: <508FEA5A.7010406@cc.hut.fi> Date: Tue, 30 Oct 2012 16:55:22 +0200 From: =?ISO-8859-1?Q?Lasse_K=E4rkk=E4inen?= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: urandom is too slow Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 765 Lines: 15 Apparently there has been little or no development on urandom even though the device is in widespread use for disk shredding and such use. The device emits data at rather slow rate of 19 MB/s even on modern hardware where other software-based PRNGs could do far better. An even better option seems to be utilizing AES for encrypting zeroes, using a random key, allowing for rates up to 500 MB/s with hardware that has AES-NI instructions. Why is urandom so slow and why isn't AES hardware acceleration utilized? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/