Securing Backbones for Embedded Home and Building Automation Networks

Abstract:

Home and Building Automation (HBA) systems control the traditional building services lighting and shading as well as heating, ventilation and air conditioning (HVAC). The main benefits of using HBA systems are the efficient use of resources with the following energy savings and the increased comfort and wellness.

Up to now, other building service types like access control, alarm and fire alarm systems have only been realised by dedicated stand-alone systems. Today a tighter integration of these isolated systems is desirable, since data which is available in one system can also be used by other ones. This integration increases the security needs of HBA systems, which have been underrated in common protocols up to now. At the same time, the use of IP backbone networks to interconnect field networks becomes more common. Unfortunately, these IP based networks are even more attractive for adversaries and prone to security attacks.

This thesis deals with the protection of communication on HBA backbone networks. The principle goal is to support embedded devices, since mainly devices with a small amount of memory and computational power are used in HBA installations. First, cryptographic principles and concepts are explained. Afterwards, state of the art protocols are discussed and rated with respect to the special requirements of HBA backbones. The main part of this thesis forms the elaboration of a new concept, satisfying these special security requirements. The proposed solution performs the necessary key management as well as the protection of the communication. While the protocol was designed with HBA networks in mind, it is also applicable to other application domains (e.g., industrial automation).