Security in networked building automation systems

Abstract

Enriching Building Automation Systems (BAS) with new services formerly provided by separate subsystems promises synergies, but increases demands on the BAS architecture. In particular, the integration of security subsystems significantly tightens security requirements on the protocol of a networked control system. First, this paper gives a survey on security in BAS. Possible threats and attacks are discussed. Weaknesses in the security mechanisms of important open networked BAS (LonWorks, BACnet, KNX/EIB) are summarized. Then, a security extension to KNX/EIB is presented. It includes several security mechanisms that guarantee data integrity, confidentiality and freshness, as well as authentication to provide secure process data and management communication. Relevant configuration related issues such as key management and distribution are also addressed.