Qualcomm Interview Question
Encryption modes, CTR, ECB, CBC..,
How HMAC works, why HMAC is designed in that way
Interview Answers
In cryptography, a keyed-hash message authentication code (HMAC) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key.
Hash-based message authentication code (HMAC) provides the server and the client each with a private key that is known only to that specific server and that specific client. The client creates a unique HMAC, or hash, per request to the server by hashing the request data with the private keys and sending it as part of a request. What makes HMAC more secure than Message Authentication Code (MAC) is that the key and the message are hashed in separate steps.