Subject: Re: Group Key Determination Algorithms --- Re: [MSEC] Session ID and Group ID

From: Ran Canetti <[email-masked]>
Date: Sat, 31 Mar 2001 13:20:34 -0500

> I think we did agree somewhere along the line that a draft(s) is needed
> to cover the "Group Key Determination Algorithms",
> which is my formal way of saying LKH, OFT, OFC, etc. (ie. Key Trees
> in general).

alternative names are "group re-keying algorithm"  or "group key update
algorithm".

> Are we limited to simply providing a variable-length payload
> for a flattened Key-Tree, or is there sufficient similarity
> among the Algorithms that we can provide a finer granularity
> standard payload?

> Also, is there a "standard" that describes how (say) the LKH algorithm
> works (in the same way that there is, say, a DES standard document)?
> I know LKH isn't an algorithms in the sense of DES, but really
> a standard is this sense is just a step-by-step description of
> how to manipulate the bits (be they keys or data).

There are many ways of going about the re-keying
process, even if we are restricting ourselves to LKH/OFT (e.g., doing
"heartbeat rekeying", different ways of generating the keys in the tree
pseudorandomly from each other, changing keys at specific times (as
suggested by Bob Briscoe a couple years back) and more). Furthremore,
there are key update algorithms that are not based on trees at all.
So, to allow for extra flexibility in the choice of the key update
algorithm it may be good to specify, in the general GKMBB framework,
only a generic payload for the key update information. Then, specific
drafts will describe how this generic payloads are interpreted by
specific key update algorithms.

Ran

_______________________________________________
msec mailing list
[email-masked]
http://www.pairlist.net/mailman/listinfo/msec