Date: Sun, 02 Feb 2003 22:19:33 +0000 From: Mark Murray <mark@grondar.org> To: "Andrey A. Chernov" <ache@nagual.pp.ru> Cc: current@FreeBSD.ORG Subject: Re: rand() is broken Message-ID: <200302022219.h12MJYaX052408@grimreaper.grondar.org> In-Reply-To: Your message of "Mon, 03 Feb 2003 01:01:28 %2B0300." <20030202220128.GC68356@nagual.pp.ru>
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"Andrey A. Chernov" writes: > On Sun, Feb 02, 2003 at 21:23:43 +0000, Mark Murray wrote: > > > > That was random(9). KERNEL random(). > > KERNEL random() can be easily implemented (better - replaced) with > arc4random(), there is no objections. But... > > 1) Implementing random(3) with RC4 is not needed, its algorithm is > already equal or better. Rubbish. :-) RC4's internal state is 256 bytes. In theory, its cycle-of-repetition is 2^(8*256) bits. The current library PRNGs are quite a bit less than that. > 2) Implementing rand(3) with RC4 can be possible only if seed (i.e. > state) can be stored in single word (due to rand_r()) restrictions. This is true. Sort of. But in this case, things get less easy. Hmm. I need to look at this some more. Thanks! M M -- Mark Murray iumop ap!sdn w,I idlaH To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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