Re: Magnus Westerlund's No Objection on draft-ietf-6man-rfc4941bis-11: (with COMMENT)

[Magnus Westerlund <[e-mail]>]

Hi Fernando,

Unfortunately I think will not be able to propose a set of adjustment. I
understand that might result in that the easiest way forward is to do nothing
here. I fully understand that, please just keep it in mind if you anyway are
doing any edits on the text if the formulation really are represenatative. 

Cheers

Magnus



On Thu, 2020-10-22 at 11:44 -0300, Fernando Gont wrote:
> Hello, Magnus,
> 
> Thanks so much for your review! In-line....
> 
> On 22/10/20 05:23, Magnus Westerlund via Datatracker wrote:
> > ----------------------------------------------------------------------
> > COMMENT:
> > ----------------------------------------------------------------------
> > 
> > I understand that this is an update of an older document resolving several
> > important issues. However, what was advanced traffic analysis 10 years ago
> > is
> > not as advanced today. The security consideration discuss some of the
> > weakness.
> > To me it appears that there are significant risks of correlation old
> > temporary
> > address passed preferred life time with the new preferred temporary address.
> 
> How would you do this at the address level? (caveat: if you do it at an 
> upper layer, I'd probably say that this is mentioned both in the 
> Security Considerations and in the discussion on persitent IDs earlier 
> on in the document).

I don't think you need high level payload analysis, 5-tuple information over
time will enable certain correlations. I understand that this is a scale not a
black and white issue. I am somewhat concerned that maybe the document indicate
that the point on this scale is somewhat more on the secure side than what I
think it is. 

> 
> > Especially if an attacker can trigger an endpoint reconnecting to a site
> > where
> > the previous temporary address was used and thus correlate the attempt to
> > force
> > reconnection combined detected use of a new temporary address to the same
> > destination. It might even be another destination but associated with the
> > same
> > remote site.
> 
> If the correlation happens at a higher layer, that's indeed possible -- 
> but out of the scope of this particular work.
> 
> 
> 
> > I have not putt this on discuss level, but my impression is that although
> > beneficial the strength of its protection might be overstated in the various
> > statements.
> 
> Please do let us know if you think that there's more that is to be 
> added, and if you have any suggestions.

> 
> Thanks!
> 
> Regards,