Re: [Mobopts] [IRSG] IRSG Poll forI-D:draft-irtf-mobopts-location-privacy-solutions

Stephen Farrell <stephen.farrell@cs.tcd.ie> Wed, 11 March 2009 16:11 UTC

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Date: Wed, 11 Mar 2009 16:12:03 +0000
From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
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Subject: Re: [Mobopts] [IRSG] IRSG Poll forI-D:draft-irtf-mobopts-location-privacy-solutions
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Eddy, Wesley M. (GRC-RCN0)[Verizon] wrote:
> You can record a vote for "ready to publish" from me.

Same here.

My non-blocking comments are below. Feel free to take 'em
on board or not, as you see fit.

Stephen.

#1 Its a bit surprising that active attackers aren't considered.
Maybe adding a justification for that would be good? I guess the
danger is that someone goes and implements all of this and claims
to have produced a "secure" solution, but in fact has only produced
something good against passive attacks.

#2 section 5.1, what mode of operation is used for the generation
of the encrypted home address? For AES I think ECB is ok, but if
a block cipher with a smaller block (e.g.  3DES) is used, then you
should probably not use ECB as that'd expose some information if
Kpm is re-used and if the home address structure is sensitive.
I've no idea if that's significant or not, but specifying CBC mode
for shorter-block ciphers would I think remove the potential
vulnerability. (3DES with ECB mode might also allow some non-obvious
cut'n'paste attacks if Kpm is re-used, though those'd be active
attacks and so presumably out of scope.)

Nits:

#1 1st sentence of section 1 is missing a word, maybe "problem"

#2, p12: s/If such/If so/