telecommunications and network security assessment

This assignment is a summative assessment of the following question sets. A minimum of 200 words for each answer is required and a minimum of one reference per answer. An introduction is not neccesary, but would be appreciated. Questions to be answered are as follows:

1. What is the difference between active and passive security threats?
2. List and briefly define 3 categories of passive and active security attacks.
3. List and briefly define at least 3 categories of security services.
4. List and briefly define at least 3 categories of security mechanisms.
5. Create a matrix highlighting the relationship between the security services and the mechanisms listed in questions 3 and 4. Place services to the left (vertically), the mechanism to the right (horizontally), then place an X for the applicable mechanisms to the services.
6. What are the essential differences of a symmetric cipher?
7. How many keys are required for two people to communicate via a symmetric cipher?
8. What is triple encryption?
9. List ways in which secret keys can be distributed to two communicating parties.
10. What are the fundamental differences between AES, DES, and 3DES?