Write a program in C that implements a bit stream cipher decoder. An elementary level bitstream

cipher is an encryption algorithm that encrypts $1$ byte of plain text at a time. This cipher uses a

given $4-$bit bit pattern as the key. The size of the encrypted message that we want to be able to

send has a maximum length of $200$ characters. The $4-$bit pattern must be duplicated to an $8-$bit

value for this to work. $($e$.$g$.,$ if we have the $4-$bit pattern $0110,$ then the $8-$bit key would be $0110$

Here is an example of encryption:

If we have the ASCII value for the letter $\text{'}t\text{'},$ then that equates to the hex value $074,$ which

represents the binary value $01110100.$ If we bitwise XOR the value with a key, say $01010101,$

then the resulting encrypted value becomes $0$x$21(00100001).$

Here is an example of decryption:

If we XOR the encrypted value with the key, we get our ASCII back. $00100001$ XOR $01010101$

becomes $01110100,$ or $\text{'}t\text{'}.$

The bit stream encryption cipher that your program must decode does a little more than this.

After encrypting the value, the program adds an alternating bit rotation twist to the algorithm.

The alternating bit rotation algorithm is such that once you have the encrypted value, it must be

rotated one bit to the left $($for example, Ob $00100001$ would become $0$b $01000010$ or $042).$

The encrypted value for the $2^{nd}$ character of the message would be rotated one bit to the right,

$3^{rd}$ character rotated left, $4^{th}$ rotated right, and so on$.$ As a further example, if $\text{'}t\text{'}$ is rotated to

the right one position, that would mean $0$b $00100001$ would become $0$b $10010000$ or $0$x$90.$