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Re: Media Queries and optimizing what data gets transferred

From: Behrang Saeedzadeh <behrangsa@gmail.com>
Date: Tue, 5 Feb 2013 10:33:19 +1100
Message-ID: <CAERAJ+8XQLKqU1hdMDkSBht9KsSgoBcfSEFOetbhquhhVJjj2A@mail.gmail.com>
To: Fred Andrews <fredandw@live.com>
Cc: Rob Crowther <robertc@boogdesign.com>, "www-style@w3.org" <www-style@w3.org>
Fred,

I am not a security/privacy guy, but you mention:

> Users that want to choose lower resolution images to speed loads and
lower bandwidth usage will need to expose some state, but less state needs
to be exposed with client-side adaptation and the state that is exposed is
less meaningful.

> The client-hints proposal requires a larger amount of client state to be
exposed and processes this on the server side to select from an expected
limited range of resources.  Keeping the selection algorithm on the client
side inherently reduces the amount of state exposed.  It would be expected
that in the majority of cases there is only a single resource to select,
and in this case the client-side adaptation need not expose any state
whereas with the client-hints proposal the client is require to blindly
expose the state in the hope that the server might be able to choose a
'optimal' resource.

Let's assume we have two kinds of companies:

1- the evil ones: you don't want your state to be exposed to them. Even
without client side hints, they can add some JS code that reveals your
client state via AJAX or something.
2- the good ones: you don't mind if your state is exposed to them, this
means both approaches are acceptable.

Am I missing something here?

Cheers,
Behrang Saeedzadeh
http://www.behrang.org


On Fri, Feb 1, 2013 at 11:35 PM, Fred Andrews <fredandw@live.com> wrote:

> Users that want to choose lower resolution images to speed loads and lower
> bandwidth usage will need to expose some state, but less state needs to be
> exposed with client-side adaptation and the state that is exposed is less
> meaningful.
>
> The client-hints proposal requires a larger amount of client state to be
> exposed and processes this on the server side to select from an expected
> limited range of resources.  Keeping the selection algorithm on the client
> side inherently reduces the amount of state exposed.  It would be expected
> that in the majority of cases there is only a single resource to select,
> and in this case the client-side adaptation need not expose any state
> whereas with the client-hints proposal the client is require to blindly
> expose the state in the hope that the server might be able to choose a
> 'optimal' resource.
>
> Further the client need not base the resource choice on actual device
> state, so the exposed state is potentially less meaningful.  For example
> with client-side adaptation the client could choose to download only the
> largest images and to downscale these as needed.  This would stop
> re-validation events when media parameters change, further lowering the
> exposed state.  For example if a client downloads lower resolution images
> it might match a device characteristic or it might be an arbitrary choice
> of the user.
>
> cheers
> Fred
>
> > Date: Fri, 1 Feb 2013 11:58:39 +0000
> > From: robertc@boogdesign.com
> > To: www-style@w3.org
>
> > Subject: Re: Media Queries and optimizing what data gets transferred
> >
> > On 01/02/2013 06:37, Fred Andrews wrote:
> > > Keeping the adaptation client-side avoids the user
> > > being forced to reveal UA state
> >
> > Surely the client-state is going to be revealed by what resources it
> > downloads anyway?
> >
> > Rob
> >
>
Received on Monday, 4 February 2013 23:33:46 GMT

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