Re: [dns-privacy] I-D Action: draft-ietf-dprive-padding-policy-01.txt

[Shane Kerr <[e-mail]>]

Hugo,

I'm curious what you mean by this. Do you really mean to propose an
option to pad every query and response message to 65K bytes? I guess I
don't object it for the sake of completion, but it seems a bit crazy.

OTOH, people use Tor for browsing, so maybe someone will actually
want to do this? ;)

Seriously though, on the query side padding beyond a few hundred bytes
is not helpful, because no queries are longer than that. Maybe on the
response side it is indeed more privacy-protecting. 

Cheers,

--
Shane

At 2017-07-04 10:40:02 +0200
Hugo Connery <[e-mail]> wrote:

> Hi Alexander (and list),
> 
> Thanks, Alexander, for your efforts on the document
> (and DKG for the empirical work).
> 
> May I suggest that another strategy is included, that of 
> "always pad to the maximum message size".  This is obviously
> wasteful, and may be recommended against.  However, I believe
> its inclusion is equivalent to the "no padding" and "fixed
> block size pad" options which are listed for completeness whilst
> providing no or very little privacy protection.
> 
> The "always pad to maximum message size" option is actually 
> the maximal privacy setting (when encrypted) but is horribly
> wasteful.
> 
> Perhaps mention it directly after the "no padding option" and
> describe that it provides maximal privacy protection, but is 
> wasteful and more balanced strategies are described below,
> including the recommended strategy.
> 
> Something like this:
> 
> ---
> 
> 4.2 Maximal Length Padding
> 
> In maximal length padding the sender pads every message to the
> maximum allowed size for a message.
> 
> Advantages: Maximal length padding, when combined with encrypted
> transport, provides the highest level of privacy protection.
> 
> Disadvantages: Maximal length padding places a heavy burden on all
> parties, including the client, all intervening network equipment, and
> the server.
> 
> Maximal length padding is not a recommended strategy.
> 
> ---
> 
> Regards,  Hugo Connery
> 
> 
> On Mon, 2017-07-03 at 23:29 +0200, Alexander Mayrhofer wrote:
> > Hi,
> > 
> > i've updated the Padding Policy draft - the main change is the
> > inclusion of an actual recommendation, essentially a blunt copy of
> > Daniel's recommendations from his empirical research work.
> > 
> > I'm looking forward to hearing a discussion around these
> > recommendations - I will subsequently update the draft based on the
> > outcome of those discussions.
> > 
> > best,
> > Alex
> > 
> > 
> > On Mon, Jul 3, 2017 at 11:25 PM, <[e-mail]> wrote:  
> > > A New Internet-Draft is available from the on-line Internet-Drafts
> > > directories.
> > > This draft is a work item of the DNS PRIVate Exchange of the IETF.
> > > 
> > >         Title           : Padding Policy for EDNS(0)
> > >         Author          : Alexander Mayrhofer
> > >         Filename        : draft-ietf-dprive-padding-policy-01.txt
> > >         Pages           : 7
> > >         Date            : 2017-07-03
> > > 
> > > Abstract:
> > >    RFC 7830 specifies the EDNS0 'Padding' option, but does not
> > > specify
> > >    the length of padding to be used in specific applications.  This
> > > memo
> > >    lists the possible options ("Padding Policies"), discusses the
> > >    implications of each of these options, and provides a
> > > recommended
> > >    option.
> > > 
> > > 
> > > The IETF datatracker status page for this draft is:
> > > https://datatracker.ietf.org/doc/draft-ietf-dprive-padding-policy/
> > > 
> > > There are also htmlized versions available at:
> > > https://tools.ietf.org/html/draft-ietf-dprive-padding-policy-01
> > > https://datatracker.ietf.org/doc/html/draft-ietf-dprive-padding-pol
> > > icy-01
> > > 
> > > A diff from the previous version is available at:
> > > https://www.ietf.org/rfcdiff?url2=draft-ietf-dprive-padding-policy-
> > > 01
> > > 
> > > 
> > > Please note that it may take a couple of minutes from the time of
> > > submission
> > > until the htmlized version and diff are available at
> > > tools.ietf.org.
> > > 
> > > Internet-Drafts are also available by anonymous FTP at:
> > > ftp://ftp.ietf.org/internet-drafts/
> > > 
> > > _______________________________________________
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> > > [e-mail]
> > > https://www.ietf.org/mailman/listinfo/dns-privacy  
> > 
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