Q$1$: Given the plaintext $\}\{0D0E0F\}$ and the key

a$.$ The original contents of State, displayed as a $44$ matrix.

b$.$ The value of State after initial AddRoundKey.

c$.$ The value of State after SubBytes.

d$.$ The value of State after ShiftRows.

e$.$ The value of State after MixColumns $($BONUS$)$

Q$2$: If a bit error occurs in the transmission of a ciphertext character in $8-$bit CFB mode, how far does the error propagate?

Q$3$: Why is it not desirable to reuse a stream cipher key?

Q$4$: In a public$-$key system using RSA, you intercept the ciphertext $C=10$ sent to a user whose public key is $e=5,n=35.$ What is the plaintext $M?$

Q$5$: Users A and B use the Diffie$-$Hellman key exchange technique with a common prime $q=71$ and a primitive root $=7.$

a$.$ If user A has private key $x_A=5,$ what is A$\text{'}$s public key $Y_A?$

b$.$ If user $B$ has private key $x_B=12,$ what is B$\text{'}$s public key $Y_B?$

c$.$ What is the shared secret key?