1. In the ECB mode of operation, if there is an error in a block of the transmitted ciphertext, only the corresponding plaintext block is affected. However, in the CBC mode, the error propagates. a. Suppose there is a bit error in the transmitted ciphertext C1. How many plaintext blocks will be affected during decryption? b. Suppose there is a bit error in the source version of P1. How many ciphertext blocks does this error propagate through? How would this affect the plaintext blocks decrypted at the receiver end?