Computer science encryption please refer to the chart to help

For the remaining questions, consider a 4-bit block cipher, described in hexadecimal by the following table: Plaintext Ciphertext Plaintext Ciphertext 4 You can think of this as a simple substitution cipher for hexadecimal digits. The table itself serves as the "key" s (6 pts) For this question, you will perform encryption and 5. decryption using the same cipher described above, but in CBC mode. Recall that you can convert hexadecimal digits to binary to do the XOR operation. a Encrypt the 4-block message Oxfeed using the above block cipher in CBC mode with an IV of 0x6 (0110 in binary) b. Decrypt the ciphertext 0x0a25 using the above cipher in CBC mode with an IV of 6