Re: [saag] Ubiquitous Encryption: content filtering

[Nico Williams <[e-mail]>]

On Mon, Jun 22, 2015 at 09:24:04PM +0000, Christian Huitema wrote:
> On Monday, June 22, 2015, at 2:12 PM, Nico Williams wrote:
> > ..
> > But it isn't just a matter of engineering the protocol.  There are security
> > problems involved in making this happen (like: [...]
> 
> And that's a good reason for not engineering a specific hole in our protocols!

Or at least being very careful about it.

> > And anyways, operators already get to do this by simply forcing users to use
> > devices from the operators (modified to have MITM CA trust anchors).
> 
> Except, we really want to close that particular hole, don't we? I

Authorized MITMing is fundamentally a part of any hierarchical
distributed, public key authentication system when the user does not
have full control of their user agent.  We can detect it in some cases
when it's unwanted, but if it is "authorized" (by the "owner" of the
device) then it's going to happen.

All the more reason to ask why we're even discussing this.

> don't know which particular combination of caching, logs and third
> party referrals we will end up standardizing, but we have to assume
> that the security stack will eventually detect this kind of meddling,
> and expose it. At a minimum, this is going to be a significant PR
> issue for any telco playing that game.

Maybe.  I assume many operators are doing this now, so whatever PR
problems might result from starting to filter, they are in the past for
many operators.

Nico
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