am doing:

$wget http://packages.ros.org/ros.key -O - | sudo apt-key add -

and I get :

--2017-03-29 15:38:00-- (try: 2) http://packages.ros.org/ros.key Connecting to packages.ros.org (packages.ros.org)|64.50.236.52|:80... connected. HTTP request sent, awaiting response... Read error (Connection reset by peer) in headers.