1 List and briefly describe the step functions that comprise the iteration function f . 2 What types of attacks are addressed by message authentication? 3 What two levels of functionality comprise a...

1
List and briefly describe the step functions that comprise the iteration function
f.

2
What types of attacks are addressed by message authentication?

3
What two levels of functionality comprise a message authentication or digital signature mechanism?

4
What are some approaches to producing message authentication?

5
When a combination of symmetric encryption and an error control code is used for message authentication, in what order must the two functions be performed?