5.5 AES-GCM Algorithm

GCM mode, developed by John Viega and David A. McGrew, employs CTR mode for data confidentiality and Galois-Field for authentication. Initially, the Message Authentication Code (MAC) is computed, followed by encryption of both the message and the MAC. It's crucial to use a nonce only once with a specific key when employing GCM. Tag length can be from 12 to 16 bytes.