[perpass] Traffic analysis

["Christian Huitema" <[e-mail]>]

The massive monitoring attacks that we know about seem to fall into three
categories: listening to the content of communications in transit, accessing
content of documents and past exchanges at a server, and analyzing traffic
to find patterns of communications and deduce social exchanges.

I think we understand the "listening on conversations" attack, and we
understand that we need more encryption. We have some good ideas for
reducing the risk of accessing contents on server, such as storing encrypted
contents on servers, or enabling distributed services so that users can
chose server locations that they find more acceptable. But I wonder whether
we have a good approach for traffic analysis.

Traffic analysis proceeds through the collection of "meta data" such as ip
headers, e-mail headers, and other forms of signaling, e.g. SIP headers. DNS
traffic analysis also falls in that category. Such data is easy to harvest
by monitoring big conduits such as backbone links or submarine cables. In
some countries, the data is collected by forcing traffic through a single
exchange or through some form of "national firewall." 

The current internet protocols and applications pay very little attention to
traffic analysis. We should obviously take the easy steps, encrypt the DNS,
e-mail and SIP connections. But when it comes to IP header analysis, we have
pretty few solutions. VPN, of course, but that requires configuration. Could
we change that?

-- Christian Huitema