$C_i=P_{i-1}$ XOR $E_K(P_i)$

$P_0=IV$

Write the formula for decrypting in the receiver side. Also illustrate encryption and

decryption diagram for this scheme.

If an error happened to $C_3$ during the transmission $($all other blocks are transmitted

correctly$),$ which blocks of plaintext could not be recovered at the receiver? Please

explain.

If an error happened to $P_3$ before encryption, actually all plaintext blocks except

$P_3$ could be recovered correctly at the receiver Please prove this.

Is it possible to execute encryption in parallel? How about decryption? Justify your

answer.

How do you think about the design of this block cipher operation design? Is it usable

or secure$?$ Justify your answer.