What specific aspect of an example code snippet for an OTP integration API ensures it demonstrates *securehandling of OTP secrets, beyond just functional integration?

The specific aspect of an example code snippet for an OTP integration API that ensures it demonstrates secure handling of OTP secrets, beyond just functional integration (which focuses on generating and verifying OTPs), is the cryptographic protection and secure lifecycle management of the shared secret key material. This refers to the underlying, unique, randomly generated string or key that enables the server and the user's authenticator to independently produce the same One-Time Passwords (OTPs). This secure handling is evident in the code snippet through the following: 1. Encryption at Rest: The code must explicitly show that when the shared secret key material is stored in a database or any other persistent storage, it is always encrypted. This means the original plaintext secret is transformed into ciphertext, which is an unr....