Explain the three key sizes for AES encryption.2. Give a reasonable guess as to computation time to guess one key.3. Describe the AES version, plaintext, key, and ciphertext.4. Explain what a block cipher is and where it might be used?5. Give examples of different types of block ciphers and their uses.6. What are the goals of network security?7. Compare and contrast the differences between a stream cipher and hash function?