Data and network security paper | Awkum or Gpgc Mardan

Semester: 6th, BS (computer science)
Time All0wed:2h:30min                                                                                          Marks: 60

Data and network security

Note: Attempt all questions: 
Q.No.1: Fill in the blanks     (6)

1: Symmetric encryption is a form of crypto system using…………..key for encryption and decryption.

2: The area of cryptography  and cryptanalysis together is called………..

3: A cryptanalysis is what the layperson calls…………..

4: Feistel cipher structure consist of………rounds.

5: DES adopted in 1977 by………..

6: Pretty good privacy is a single person effort is developed by………….

Q.No.2: Give short answers to the following questions.                (14)
             
>What is active and passive attack?
>What is the different between block and stream cipher
>How can we define CIA
>What is cryptology.
>Define Kerberos?.
>What is digital signature?
>How can we define hash function

SECTION B                                       (40)

Q.NO.3    what is encryption ?Explain different types of encryption
                  Techniques with examples.
Q.NO.4   State AES structure .Also give AES key expansion algorithm.
                draw label diagram.
Q.NO.5   what are the principle elements of public key crypto system.

Q.NO.6   what is DES? Explain DES encryption algorithm with label diagram.