Bob sends a message to Alice. He sends the message in plaintext, but first he uses a Message Authentication Code (MAC), with a secret key he shares with Alice, to create a cryptographic checksum for the message. He sends the cryptographic checksum along with the message.Upon receipt of the message, Alice uses the same MAC algorithm and key to generate a cryptographic checksum. She compares the two checksums and finds them to be identical. As a result, what two things is Alice assured of about the message? _______________ What is she not assured of? ______________________