Problem
1. In RSA, given n = 12091, e = 13, and d = 3653 encrypt the message "THIS IS TOUGH" using the 00 to 26 encoding scheme. Decrypt the ciphertext to find the original message. Use 4-digit plaintext or ciphertext blocks.
2. In RSA, why can't Bob choose 1 as the public key e?
3. Explain why private-public keys cannot be used in creating a MAC.