Cryptography

1. Write short answers for each one of them a) Method of concealing data including messages, files, keys and passwords is known as: b) Method to protect blocks of data from being altered is known as c) What are three parts of CIA triad? d) What is the main difference between accountability and availability e) What is the ITU-T recommended security architecture for OSI called? 2. Explain the differences between active and passive attacks. Give suitable examples. 3. What are the four categories of active attack? Write short notes for each of them. 4. Consider an automated teller machine (ATM) in which users provide a personal identification number (PIN) and a card for account access. Give examples of confidentiality, integrity, and availability requirements associated with the system and, in each case, indicate the degree of importance of the requirement. 5. Make a sketch of model for network security and show how cryptography plays an important role in it