From owner-freebsd-bugs Sat Sep 22 12:20:51 2001 Delivered-To: freebsd-bugs@freebsd.org Received: from kaka.blahonga.org (kaka.blahonga.org [213.80.9.175]) by hub.freebsd.org (Postfix) with ESMTP id E8BFC37B41E for ; Sat, 22 Sep 2001 12:20:42 -0700 (PDT) Received: (from art@localhost) by kaka.blahonga.org (8.10.1/8.10.1) id f8MJHEn30091; Sat, 22 Sep 2001 21:17:14 +0200 (CEST) To: "June Carey" Cc: bugs@openbsd.org, bugs@freebsd.org Subject: Re: OpenBSD-2.9 random devices References: From: Artur Grabowski Date: 22 Sep 2001 21:17:13 +0200 In-Reply-To: "June Carey"'s message of "Sat, 22 Sep 2001 18:52:16 +0000" Message-ID: <878zf79gsm.fsf@kaka.blahonga.org> Lines: 42 User-Agent: Gnus/5.0807 (Gnus v5.8.7) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org "June Carey" writes: > Hi. > > In the OpenBSD-2.9 random(4) manual pages, it says: "The entropy > pool is converted into output data using MD5"; /dev/srandom, > /dev/urandom. > > I believe the implementation of these devices were "taken" from FreeBSD, > hence the Cc:. > > I suggest that the MD5 algorithm is removed and replaced with what I > call the "XOR-fold-technique". As I'm sure you know, the one-time-pad > cipher consists of a key-stream synchronously XOR'd with a data-stream. > > The "XOR-fold-technique" is the same thing, but applied to only one > stream. For example, if you have a (secret) 16-byte quantity, you half > it in size (8-bytes) and XOR one half with the other. The product is > as secure as the one-time-pad cipher, i.e. it is a perfect one-way > "hash". > > > The replacement of MD5 with "XOR-fold" has the following advantages: > > (1) Guaranteed one-way function; MD5 is at best supposition. > (2) Massive performance increase. > (3) The algorithm automatically scales to the input size, whereas MD5 > produces a constant sized output (128-bits from memory ?) > > > Disadvantages: > > None ? I'm sorry, but taking cryptographic advise from someone completly unknown mailing from hotmail is not good cryptographical practice. Publish a paper, make comparsions between your method and other methods, have some known cryptographers analyze it and come back in 5 years, then maybe we'll have something to talk about. //art To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message