Assume that you are in a band, and you're working on the lyrics for a new song with your bandmates. Your band is very famous. so to protect your communications you encrypt your messages, and use an HMAC to provide authentication. One of the other band members, let's call him John, has a new girlfriend, let's call her Yoko, who is a bad influence. You've just received a file containing John's suggested changes, along with the HMAC tag which is:

C$049$ F$080$ B$913$ EC C$9$ A$038$ DC A$2$ BA $966$ E $3710$ D$77$F

$57$ CAF$664$ E$868278C$ E$61$ F $86$ FB $14$

You decrypt the file and save the plain text as the file Test$2$HMACLyrics.txt$.$ You suspect that Yoko may have altered the lyrics, so you decide to check the HMAC tag. The HMAC key your band decided to use is the band's name, the beatles. $($Make sure and include the in the key.$)$

What can you determine about the song lyrics?

Hints and tips. Use Cryptool to calculate the HMAC tag of the file Test$2$HMACLyrics.txt$.$ Ensure that Cryptool is set to use the SHA$-256$ hash and $H(k,H(k,m))$ : double hashing $($RFC$2104)$

The lyrics are authentic.

That darn Yoko, or someone, altered the lyrics. If John doesn't get