Implement RC$4,$ the most popular symmetric stream cipher $($using Java$).$

THE RC$4$ ALGORITHM:

$\frac{?}{?}*$ Initialization $*/$

for $i=0$ to $255$ do

$s[i]=i$;

keylen$]$;

$\frac{?}{?}**$ Initial Permutation of $S*\frac{*}{?}$

$j=0$;

for $i=0$ to $255$ do

$j=(j+s[i]+T[i])mod256$;

Swap $($S$[$i$],S[j]$;

$/*$ Stream Generation $*/$

$i,j=0$;

while $($true$)$

$i=(i+1)mod256$;

$j=(j+s[i])mod256$;

Swap $($s$[$i$],s[j])$;

$t=(S[i]+s[j])mod256$;

$k=s[t]$;

To encrypt, XOR the value $k$ with the next block of plaintext. To decrypt, XOR the value $k$ with

the next block of ciphertext.

Program Requirements: The program should prompt the user to enter the key length $($in

blocks$),$ the key $($key length number of blocks$),$ size of input $($in blocks$)$ and the plain text $($size

number of blocks$).$ The program should then display the cipher text as well as the decrypted

cipher text $($which is the plain text$).$ In Java, XOR can be performed using $"{?}^{{?}^{?}}"$ operator.

Sample input$/$output is provided in the next page.