imp qus for ns&c for 2nd mid

1. write briefly authentication Requirements and functions?
2. explain message authentication and hash function.
3. explain security of hash functions and MACS
4. write briefly message digest _Algorithm.
5. what is the difference between secure hash function and hash function.
6. explain RIPEMD-160,HMAC
7. explain Digital signature standards.
8. Explain with neat diagram Kerberos, X.509 directory authentication service.
9. write down PGP &    S/MIME.
10. explain combining security Associations
11. explain IP security Architecture Authentication.
12. Explain Encapsulation security payload.
13. explain key management.
14. what is meant by web security & requirements.
15. explain secure socket layer and transport layer security.
16. explain secure electron transaction with example?
17. write short notes
1. intruders.
2. Virsuse and related threats.

      18. explain fire wasll design principles trusted systems.