Blash Script file Information 2022

Problem 1
Below are the steps –
12 – 1100 = 1*8 + 1*4 + 0*2 + 0*1
7 – 0111 = 0*8 + 1*4 + 1*2 + 1*1
2 – 0010 = 0*8 + 0*4 + 1*2 + 0*1
Problem 2
Below is the bash script –
** I have enclosed the bash script file as well.
Problem 3
Given:

Cipher Key: 2b7e151628aed2a6abf7158809cf4f3c
NK = 4
w[0] = 2b7e1516
w[1] = 28aed2a6
w[2] = abf771588
w[3] = 09cf4f3c
Pseudo Code of Key Expansion Algorithm shown in figure, shows
//The key expansion function that takes cipher key and Nk as input
KeyExpansion (byte key[4*Nk], wordw[Nb* (Nr+1)], Nk)
begin
word temp //The key is assigned to a temporary variable
i = 0
while (i < Nk)
w[i] = word(key[4*i], key[4*i+1], key[4*i+2], key[4*i+3]) // The results w[0], w[1],
w[2], w[3] are obtained
i=i+1
end while
i = Nk
while ( i<Nb * (Nr+1))
temp = w[i-1]
if ( i mod Nk = 0)
temp = SubWord (RotWord (temp) XOR Rcon[i/Nk])
else if (Nk > 6 and i mod Nk = 4)
temp = SubWord (temp)
end if
w[i] = w[i-Nk] XOR temp
i = i+1