Key set management in networked building automation systems using multiple key servers

With the integration of security critical applications into traditional building automation systems, a comprehensive security concept is mandatory. Most important, transmitted data have to be secured using cryptographic techniques. However, even if the used cryptographic algorithms are perfectly secure, the overall security highly depends on the non-disclosure of the used shared secrets. Therefore, this paper targets the management of these shared secrets and the necessary infrastructure used to manage them. Finally, to eliminate a single point of failure in this infrastructure, a redundancy concept featuring multiple key servers is presented.