4.1 List ways in which secret keys can be distributed to two communicating parties. 4.2 What is the difference between a session key and a master key? 4.3 What is a key distribution center? 4.4 Wha

4.1 List ways in which secret keys can be distributed to two communicating parties. 4.2 What is the difference between a session key and a master key? 4.3 What is a key distribution center? 4.4 What entities constitute a full-service Kerberos environment? 4.5 In the context of Kerberos, what is a realm? 4.6 What are the principal differences between version 4 and version 5 of Kerberos? 4.7 What is a nonce? 4.8 What are two different uses of public-key cryptography related to key distribution? 4.9 What are the essential ingredients of a public-key directory? 4.10 What is a public-key certificate? 4.11 What are the requirements for the use of a public-key certificate scheme? 4.12 What is the purpose of the X.509 standard? 4.13 What is a chain of certificates? 4.14 How is an X.509 certificate revoked?