KNX Secure Guide: 1. Introduction

So far, the data transmitted in a KNX automation installation was open and could be read and manipulated by anyone with some knowledge with access to the KNX medium, so that security is guaranteed by preventing access to the KNX bus or to the devices. The new KNX Secure protocols add additional security to the communications in a KNX installation to prevent such kind of attacks.

Devices with KNX secure will be able to communicate securely with ETS and any other secure device, as they will incorporate system for authentication and encryption of the information.

There are two types of KNX security that can be implemented simultaneously in the same installation:

• KNX Data Secure: secures the communication within a KNX installation.
• KNX IP Secure: for KNX installations with IP communication, secures communication via IP network.

A secure KNX device refers to a device that has the basic capability to enable secure communication, although it is not always required to do so. An unsecured communication on secured KNX devices is equal to communication established between devices without KNX security.

The use of security depends on two significant settings in the ETS project:

• Commissioning security: sets whether, during the commissioning, the communication with ETS should be secure or not and opens up the possibility of activating the runtime security.
• Runtime security: sets whether during runtime, communication between devices should be secure or not. In other words, it determines which group addresses are to be secure. In order to activate the security during runtime, the commissioning security must be activated.

The activation of security on KNX Secure devices is optional. If it is activated, it is set individually in the group addresses, so that all or only a part of the objects can be secured, while the rest can function normally with non-secured devices. In other words, devices with and without KNX Secure can coexist in the same installation.