Exercise $1$

Using the RC$4$ Stream cipher algorithm. Suppose the key consists of the following seven bytes:

key $=(01A,02B,03C,04D,05E,06F,077).$

Find the permutation $S$ after the initialization phase.

Find the permutation $S$ after generating $1$ byte of the keystream.

Find the byte.

Exercise $2$

Write a C program that implement the RC$4$ Stream cipher algorithm. Suppose the key consists of the following seven bytes:

key $=(01A,02B,03C,04D,05E,06F,077).$

The program must display

the permutation $S$ after the initialization phase.

the permutation $S$ after generating $1$ byte of the keystream and the byte

the permutation $S$ after generating $2$ byte of the keystream and the last byte.

the permutation $S$ after generating $100$ byte of the keystream and the last $100$ bytes in a text file.