Which authentication method should you use?

You have an Azure IoT hub that is being taken from prototype to production.

You plan to connect IoT devices to the IoT hub. The devices have hardware security modules (HSMs). You need to use the most secure authentication method between the devices and the IoT hub. Company

policy prohibits the use of internally generated certificates.

Which authentication method should you use?
A . an X.509 self-signed certificate
B. a certificate thumbprint
C. a symmetric key
D. An X.509 certificate signed by a root certification authority (CA).

Answer: D

Explanation:

Purchase X.509 certificates from a root certificate authority (CA). This method is recommended for production environments.

The hardware security module, or HSM, is used for secure, hardware-based storage of device secrets, and is the most secure form of secret storage. Both X.509 certificates and SAS tokens can be stored in the HSM

Reference: https://docs.microsoft.com/en-us/azure/iot-dps/concepts-security