Wired: Echelon Furor Ends in a Whimper

[David Wagner]

Peter Fairbrother  wrote:
>Implementing protections against passive-only interception is a bit like
>installing a reinforced, fortified door and leaving the windows unlocked.

If your goal is to protect European communications from being intercepted
by Echelon-like systems (and that was the context of this thread, after
all), it might be plenty good enough.

I failed to grok the rest of your note.  You cannot deter active MITM
attacks without some authenticated, shared information (whether shared
key material, or authenticated public keys for the participants).