Azure IoT Hub Device Authentication
Question
Azure IoT provides a number of patterns and options to design and implement security in your IoT solutions.
One of the key components of the security architecture is how the devices authenticate themselves to IoT hub.
Security tokens and X.509 certificates are two ways of authentication you can choose from.
Which of the following statements is not true?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer: D.
Option A is incorrect because the security tokens provide limited access to resources both from the perspectives of time and the scope.
Option B is incorrect because security tokens can also be used with symmetric key solutions, i.e.
they don't require use of X.509 certificates.
This can be a good solution when less security is acceptable.
Option C is incorrect because either shared access signatures or symmetric keys can be used to sign security tokens.
Option D is CORRECT because the X.509 authentication method is only applicable for devices which have a secure storage to store the private keys securely.
(It is typically not applicable for low-resource sensors.)
References:
Sure, I can provide you with a detailed explanation of each statement and which one is not true.
A. Security tokens are limited in validity and in scope. This statement is true. Security tokens are time-bound and have a limited scope. They are valid only for a specific duration and for a particular IoT hub or device scope.
B. The security token method can be used without X.509 authentication. This statement is true. The security token method can be used as an alternative to X.509 certificate-based authentication for devices that cannot use X.509 certificates. In such cases, devices can use the device key to generate a security token and authenticate with the IoT hub.
C. Shared access signatures can be used to sign security tokens. This statement is also true. Shared Access Signatures (SAS) can be used to sign security tokens. SAS is a secure way of sharing access to resources without revealing the access key. It can be used to authenticate devices or applications to access Azure IoT Hub.
D. The X.509 method is appropriate for any type of devices. This statement is not true. While X.509 certificates provide strong security for IoT devices, they may not be suitable for all types of devices. For example, devices with limited processing power or storage may not be able to handle X.509 certificates efficiently. In such cases, other authentication methods such as security tokens or device keys may be more appropriate.
In summary, statement D is not true as X.509 certificates may not be suitable for all types of devices. The other statements are all true, as security tokens are time-bound and have a limited scope, the security token method can be used without X.509 authentication, and shared access signatures can be used to sign security tokens.
