Re: [saag] Ubiquitous Encryption: content filtering

[Yoav Nir <[e-mail]>]

> On Jun 23, 2015, at 11:59 AM, Kathleen Moriarty <[e-mail]> wrote:
> 
> Thanks for the discussion on this, it's helpful to get this right for documentation purposes.  I'd split out MiTM activities of this sort for enterprises vs. the same done at the service provider level because of employee agreements.  I also choose not to go to many sites from behind a firewall and hope others do too when signaled that there is a certificate mismatch.

I’m not sure if that distinction is meaningful. The technology for interception is the same whether it is used to scan downloaded files for malware or to scan Facebook posts for insufficient appreciation of our Dear Leader.

Employees in a corporate environment are supposedly informed, but corporate computers and devices may come pre-installed with the interception certificate. Even as a conscientious vendor, there is no way I can enforce that corporate IT properly informs the employees. 

Similarly, we’ve seen interception used at service providers at the behest of governments. In some countries devices come pre-installed with the government interception certificate. This makes it transparent to the citizens. Again, it would be nice if citizens at least knew this was happening, but those governments tend to not be “nice”.  At least ISPs don’t have the power to manipulate the endpoints (though in the early days of broadband they would ask you to install a “dialer” - if I were a more suspicious person…), but they do when they work for the government. 

Ideally a solution would reveal the presence of a MITM to both client and server. All solutions discussed thus far can reveal things to the client, but do nothing for the server. I would like to have servers such as financial institutions and medical services be able to enforce a policy where they don’t provide a service through a middlebox. Doing it now requires installing their own client on the user’s machine, which seems to be a trend in mobile, but is not something we should require.

Yoav