Date: Sat, 23 Aug 2003 11:55:58 -0500 (CDT) From: Mike Silbersack <silby@silby.com> To: David Schultz <das@FreeBSD.ORG> Cc: cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/libkern arc4random.c Message-ID: <20030823115345.N7877@odysseus.silby.com> In-Reply-To: <20030823091918.GA8236@HAL9000.homeunix.com> References: <200308151911.h7FJBkOI003844@grimreaper.grondar.org> <20030823091918.GA8236@HAL9000.homeunix.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 23 Aug 2003, David Schultz wrote: > Another test suite, which seems to be highly regarded, is > Marsaglia's DIEHARD package. The sources themselves are probably > on the web somewhere, and there's some sample output from the last > time the subject of randomness came up on the lists at > http://www.csua.berkeley.edu/~das/marsaglia/ . > I can run it again if there's interest. Can you turn it into a port? :) > I'm not a cryptographer, but FWIW, I'm told that there are > statistical tests that can differentiate an ARC4 sequence from a > truly random sequence. However, it takes something like 2^31 bits > of data to detect the statistical bias. According to the paper referenced in the comment, the pattern is *especially* apparent in the first 256 words of output, which is why they should be thrown out. (From my original reading of the paper, I was unable to determine if by his terminology he meant the first 256 bytes, words, dwords, quadwords, or what. So I throw away the first 256 dwords, just to be safe.) Mike "Silby" Silbersack
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030823115345.N7877>