Security properties – what do we expect?
We are now going to look into an embedded system. But what do we want to find in there? What do we want to test and why do we want to verify that it is done properly?
Not every system will require each of these functions (communication, maintenance, self-test, and so on), but these functions should at least have been considered by the client in their security requirements. From there, either the security properties are integrated as risk mitigation or the linked risk has been formally accepted within their risk management process – that is, if these risk management steps were followed in the product design.
Very often, these steps (establishing formal security requirements and integrating the unfulfilled mitigations in the risk management process) are overlooked. This is bad for the product, but this is very common. These are two findings for your report right here!
Now, let's look at the usual functions of a system...