CY-503-B Network Security - Nov 2022 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain in detail cipher block modes of operation with merits and demerits.
   How to answer

   • Define block cipher modes of operation and need for modes
   • Explain ECB, CBC, CFB, OFB, CTR with operation diagrams
   • Merits and demerits of each mode - error propagation, parallelism, IV requirement
   • Applications and comparison summary
2. 7 Marks
   bExplain the stream cipher algorithm RC4.
   How to answer

   • Define stream cipher and RC4 as variable-key stream cipher
   • Explain KSA and PRGA steps
   • Keystream generation and XOR encryption/decryption
   • Security properties, uses and weaknesses
3. 7 Marks
   aExplain HMAC algorithm in detail.
   How to answer

   • Define HMAC purpose and keys
   • Explain structure with inner and outer hash, ipad/opad
   • Steps and formula HMAC(K,M)
   • Security and applications in integrity and authentication
4. 7 Marks
   bWhat is VPN? Write about the different types of VPN's.
   How to answer

   • Define VPN and its purpose
   • Explain types - site-to-site, remote-access, SSL/TLS, IPSec VPN
   • Tunneling and encryption basics
   • Uses, advantages and examples
5. 7 Marks
   aExplain with a neat diagram how PGP provides authentication and confidentiality for email security?
   How to answer

   • Define PGP and its email security services
   • Explain authentication steps - hash, sign, compress
   • Explain confidentiality steps - session key, public-key and symmetric encryption
   • Combined authentication+confidentiality flow with neat diagram
6. 7 Marks
   bExplain the transport and tunnel mode of operation for ESP in IP Security.
   How to answer

   • Define ESP in IPSec
   • Explain transport mode - header format and protection scope
   • Explain tunnel mode - encapsulation of entire IP packet
   • Comparison and use cases with diagrams
7. 7 Marks
   aWrite about Host based Intrusion detection systems.
   How to answer

   • Define IDS and host-based IDS
   • Architecture and data sources - logs, system calls
   • Detection techniques - anomaly and signature
   • Advantages, limitations and examples
8. 7 Marks
   bDefine Firewall? Write about packet filtering firewalls.
   How to answer

   • Define firewall and its purpose
   • Explain packet filtering concept and rule tables
   • Filtering on IP, port, protocol with example
   • Strengths and limitations
9. 7 Marks
   aWrite the merits and demerits of Firewalls.
   How to answer

   • Define firewall role in network security
   • List merits - access control, monitoring, NAT, logging
   • List demerits - insider attacks, malware, performance, bypass
   • Concluding assessment
10. 7 Marks
    bExplain the WAP architecture with suitable diagram.
    How to answer

    • Define WAP and need for wireless access
    • Explain WAP architecture components - client, gateway, origin server
    • Protocol stack and working flow
    • Neat labeled diagram
11. 7 Marks
    aExplain WLAN protocol stack and MPDU format with suitable diagram.
    How to answer

    • Define WLAN protocol stack layers
    • Explain MAC, PHY and LLC functions
    • Describe MPDU frame format and fields
    • Suitable stack and frame diagrams
12. 7 Marks
    bDiscuss in detail about WLAN security.
    How to answer

    • Define WLAN threats - eavesdropping, rogue AP, DoS
    • Explain WEP, WPA, WPA2/WPA3 and 802.11i
    • Authentication and encryption mechanisms
    • Best practices for WLAN security
13. 14 Marks
    Explain in detail about Secure Electronic Transaction with suitable example.
    How to answer

    • Define SET and its objectives
    • Explain participants - cardholder, merchant, acquirer, CA
    • Explain dual signature and transaction steps with example
    • Features and advantages
14. 14 Marks
    Write short notes on any two of the following.

    1. a)Differentiate between block and stream ciphers
    2. b)Smart cards and Biometrics
    3. c)Proxy and Personal Firewalls
    4. d)Web traffic security approaches
    How to answer

    • Lead-in about attempting any two topics
    • For each chosen topic: definition, key points and diagram/table if needed
    • Comparison or types where applicable
    • Applications, merits/limitations