Asymmetric ciphers' irreversible operations make them more secure. This chapter covered various asymmetric operations. What asymmetric operations can you think of?

Decrypt: Encryption and decryption are mathematical inverses using the Caesar/Rail Fence Cipher Key is 0x7F in hexide

This may be used to explain why certain block cypher modes of operation utilise encryption alone, whereas others use encryption and decryption together:

A block cipher with a random key is most like a Choose one: Private random function Public random permutation Private random permutation Public random function

The Feistel cipher design exactly what you'd expect it to be. How about a Feistel cipher-based contemporary block cipher?

Perform the Encryption and then the Decryption for the Hill Cipher where the Plain text: "POH" and the key is: "GYBNQKURP".

Cryptanalysis can be achieved through exhaustive key search for a Caesar Cipher. Explain how this would be accomplished.

Please describe the techniques of Substitution Cipher and Transposition Cipher.

4. Choose any 1 cipher methods of your choice and explain its working with example

Let the encryption keyword of a monoalphabetic cipher be ROME.   (a) Show the encryption key in the table form.   (b) Show the decryption key in the table form.   (c) Obtain ciphertext for the following message sentence: Rome wasn’t built in a day.