Practical Internet of Things Security - Second Edition

Persistent configuration management

As with any IT system, configuration management is an important aspect of the security of your IoT system. CSPs offer features that support the real-time management of your device configurations, even when the devices are disconnected from the cloud.

Both AWS and Azure offer users the ability to access and modify the state of an edge device even when that device is offline or unreachable. AWS has termed this ability Thing Shadows, while Azure uses the term device twins.

In both cases, device configuration state is stored in a JSON document in the cloud. So, for example, if an MQTT-enabled light bulb is offline, a MQTT command can be sent to the virtual things repository to change its color. When the lightbulb ...