International humanitarian law creates an obligation to mark air- and seaborne medical transport with distinctive emblems or in special cases to use distinctive signals in order to guarantee their adequate protection. Since long-distance cyber-attacks are conducted in an isolated fifth dimension of warfare (cyberspace), visual contact with the attacked physical object may be lacking (unless conducted as part of a bigger operation with reconnaissance units or satellites). That raises the question how to “mark” the computers of medical transport online in order to inform the attacker of their special status, as well as to ensure its respect (Melzer, 2011).