Security in Building Automation Systems

Building automation systems are traditionally concerned with the control of heating, ventilation, and air conditioning, as well as lighting and shading, systems. They have their origin in a time where security has been considered as a side issue at best. Nowadays, with the rising desire to integrate security-critical services that were formerly provided by isolated subsystems, security must no longer be neglected. Thus, the development of a comprehensive security concept is of utmost importance. This paper starts with a security threat analysis and identifies the challenges of providing security in the building automation domain. Afterward, the security mechanisms of available standards are thoroughly analyzed. Finally, two approaches that provide both secure communication and secure execution of possibly untrusted control applications are presented.