1. (a) Draw a decryption diagram for CBC. (b) Alice has a message to send and she breaks it into 10 blocks (M1, ..., M10) and encrypts them using AES in CBC mode and sends Bob C1, ..., C10. Suppose during transmission of ciphertext, there are two bit errors in the transmission of C4 and Bob knows that. Explain which M;'s will Bob correctly decrypt? and which ones are systematically wrong? Briefly explain. (c) We saw that the encryption in CBC mode is sequential. Can the decryption be parallelized? briefly explain. 1. (a) Draw a decryption diagram for CBC. (b) Alice has a message to send and she breaks it into 10 blocks (M1, ..., M10) and encrypts them using AES in CBC mode and sends Bob C1, ..., C10. Suppose during transmission of ciphertext, there are two bit errors in the transmission of C4 and Bob knows that. Explain which M;'s will Bob correctly decrypt? and which ones are systematically wrong? Briefly explain. (c) We saw that the encryption in CBC mode is sequential. Can the decryption be parallelized? briefly explain