Fwd: Re: Fwd: Re: [office] Fwd: OASIS and encryption

[David Faure <faure@kde.org>]

----------  Forwarded Message  ----------

Subject: Re: Fwd: Re: [office] Fwd: OASIS and encryption
Date: Tuesday 07 September 2004 21:58
From: Brad Hards <bradh@frogmouth.net>
To: David Faure <faure@kde.org>

[for onforwarding]
On Wed, 1 Sep 2004 15:50 pm, David Faure wrote:
> After reviewing PKCS#5 I am of the opinion that we should do something
> in order to better define the key dervation process. If some
> implementation would for some reason choose an other PRNG function for
> salt creation, documents encrypted by that implementation could not be
> decrypted by an implementation using the now standard HMAC function.
I think we should support a range of algorithms. But I don't know enough about 
crypto to identify them now.

> I see two possibilities: we might either want to specify HMAC as a MUST
> in the specification, or we might include a new property that holds a
> name identfying the method used to generate the salt in the manifest.
> Since crypto related algorithms are sometimes obsoleted because of
> discovered weaknesses (MD5 or SHA-0 in recent times), specifying the
> encryption and key dervation mechanism in the manifest might be the way
> to go.
Also, the number of iterations shouldn't be hardcoded into the spec. As OOo 
does now, the spec should say that the number is in the manifest, and maybe 
suggest that at least 2^10 should be used.

Brad


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-- 
David Faure, faure@kde.org, sponsored by Trolltech to work on KDE,
Konqueror (http://www.konqueror.org), and KOffice (http://www.koffice.org).