The summer school will take place in the recently built ID building which is home of the Horst Görtz Institute of IT-Security (HGI).
The easiest way to get to the Ruhr University is by subway. Just go to the basement of the Bochum Central Station and take the subway U35, direction "Hustadt", and get out after about 10 minutes at the stop "Lennershof". A ticket for the local public transport is included in your conference fee.
Take the stairs. Your are now on the street "Im Westenfeld". Follow the street till the end. Now you turn right on "Lennershofstraße". After about 1 min you can see building ID on the left side. Enter the building and proceed through the corridor. You will be guided by signs to the room ID 04 / 471 where the summer school is held. In case you get lost you can ask at the information desk.