Q5 (20 pts) Mode of Encryption. Let the upper-case letters A,B,,Z be represented by the numbers 0,1,,25, the lower-case letters a,b,,z be represented by the numbers 26,27,,51, the digits 0,1,,9 be represented by 52,53,,61. Let "-" be represented by 62 and " " (space character) be represented by 63 . Therefore, each character is represented by 6 bits. We define block cipher performs 3 steps: 1. Right rotate by 1 : Shift the bits by one to the right and move the right-most bit to the left-most bit. 2. XOR with 6 bit key. Encrypt the message "Nasa" using a. Electronic Code Book mode (ECB) b. Cipher Block Chaining mode (CBC) c. Output Feedback mode (OFB) d. Cipher Feedback mode (CFB) Use (100100)2 as the key. There will be six block (one block for each letter). Use the same key for each block. Use IV = 010101 in CBC, OFB, and CFB modes. You should show the output after each step