WebApp Sec mailing list archives
Re: key material
From: "Greg Kilford" <greg_kilford () hotmail com>
Date: Fri, 23 Apr 2004 08:14:09 -0600
Our discussion of A is as a generic bit stream of assumingly random nature from an arbitrary source, eg. mouse movements, etc. But seriously speaking, it could be anything. More importantly, what size of A would suffice in seeding the PRNG sufficiently for the output stream O after the seeding would be of sufficient entropy for RSA 1024/2048 modulo key materials. Some of us are inclined to believe A should be of size/length 1024/2048 bits before the PRNG is seeded sufficiently while a few of my pals are suggesting 64/128 or even 192 bits would suffice. Very disparate gut feelings...
From: Peter Conrad <conrad () tivano de> To: webappsec () securityfocus com Subject: Re: key material Date: Fri, 23 Apr 2004 10:05:23 +0200 Hi, On Thu, Apr 22, 2004 at 11:29:36AM -0600, Greg Kilford wrote: >> I was juz discussing with my pals the other day on the appropriate initial > input bit size to seed a PRNG of the structure below for it to be used to > generate the random bits for RSA key material of modulus 1024 bits or 2048 > bits. Anyone know what would be the ideal length/size of A so that there > is sufficient entropy to generate the key material for RSA 1024/2048 bits> keys?that'll depend on how you use the output of the PRNG to generate an RSA key.As a general rule I'd say A should have one bit of entropy for every bit of O that you use. You didn't tell us anything about how A is constructed, so we can't say how long it should be. Bye, Peter -- Peter Conrad Tel: +49 6102 / 80 99 072 [ t]ivano Software GmbH Fax: +49 6102 / 80 99 071 Bahnhofstr. 18 http://www.tivano.de/ 63263 Neu-Isenburg Germany
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Current thread:
- key material Greg Kilford (Apr 22)
- Re: key material Peter Conrad (Apr 23)
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- Re: key material Greg Kilford (Apr 23)