[WireGuard] auth-only wireguard

[Bruno Wolff III]

On Thu, Oct 06, 2016 at 19:32:36 +0200,
  "Jason A. Donenfeld" <Jason at zx2c4.com> wrote:
>On Thu, Oct 6, 2016 at 5:03 PM, Bruno Wolff III <bruno at wolff.to> wrote:
>> Without encryption you authentication won't be useful against attackers that
>> can modify packets or insert packets with the source address of your
>> contact.
>
>Either I've misunderstood you, or this is completely inaccurate.
>
>What do you mean exactly?

Someone able to watch and modify traffic can wait for authentication to occur 
and then take over the connection. So you don't know you are still 
communicating with the party that did the authentication. You need something 
protecting message integrity which is normally based on encryption, but I 
think there might be ways to do that with just hashing.