QUESTION 4 i. Given the following encryption scheme with 1-byte blocks, encrypt the string (expressed in hexa) "BABA" and key as "C5" with CFB using IV-D2. The encryption scheme using 1-byte block size is as follows: Step 1. Substitute each of the 2 hexa characters using the following S-box. In 01 23 456 7 8 9A BC D E F Step 2. Perform bit-wise XOR of the key with the 8-bit output of step 1 (i) Using the same information as above decrypt "BABA" with OFB using IV-D2. QUESTION 4 i. Given the following encryption scheme with 1-byte blocks, encrypt the string (expressed in hexa) "BABA" and key as "C5" with CFB using IV-D2. The encryption scheme using 1-byte block size is as follows: Step 1. Substitute each of the 2 hexa characters using the following S-box. In 01 23 456 7 8 9A BC D E F Step 2. Perform bit-wise XOR of the key with the 8-bit output of step 1 (i) Using the same information as above decrypt "BABA" with OFB using IV-D2