You are operating an industrial IoT infrastructure with a number of devices using X.509 attestation.
The devices monitor safety conditions of chemical reactors.
All the devices have been provisioned through the device provisioning service using individual enrollment.
Now two of the reactors are going to be dismounted, and the related devices must be deprovisioned and sold.
Your task is to ensure that the devices will not be able to re-enroll in the future.
You have disabled the devices' enrollment entry in the DPS, and deleted the identity registries from the IoT Hub.
Can you be sure that the devices will not be able to re-enroll?
Click on the arrows to vote for the correct answer
A. B.Correct Answer: A.
Option A is CORRECT because in case an enabled enrollment group exists on the DPS, which uses a signing certificate of the devices, there is a risk that the devices can re-enroll, even if their enrollment entry has been deleted.
Therefore, disabling the enrollment entry instead of deleting it is the right solution.
Option B is incorrect because if you delete an individual enrollment of devices using X.509 attestation and an enabled enrollment group exists for a signing certificate in the devices' certificate chain, the devices still can re-enroll.
References:
Based on the information provided, it is likely that the devices will not be able to re-enroll in the future. However, there are a few factors to consider:
First, the devices have been provisioned using X.509 attestation, which is a secure way to establish the identity of a device. X.509 certificates are issued by a trusted third party, and they include information such as the device ID and public key. When a device tries to enroll in a DPS, it needs to present a valid X.509 certificate to prove its identity.
Second, the devices have been provisioned through the device provisioning service using individual enrollment. This means that each device has a unique identity that is tied to its X.509 certificate. When a device is deprovisioned, its identity is deleted from the DPS.
Third, the identity registries for the devices have been deleted from the IoT Hub. This means that even if a device were to somehow obtain a valid X.509 certificate in the future, it would not be able to connect to the IoT Hub because its identity is no longer registered there.
Based on these factors, it is unlikely that the devices will be able to re-enroll in the future. However, it is worth noting that there is always a small possibility of a security breach or a technical error that could allow a device to reconnect to the infrastructure. Therefore, it is important to monitor the infrastructure and take appropriate measures if any unexpected activity is detected.