Computer Networking – Network Security MCQs

This Portion of Computer Networking contains Computer Networking Network Security MCQs (Multiple Choice Questions and Answers).

This Section covers below lists of topics.

1 INTRODUCTION
• Security Goals
• Attacks
• Services and Techniques

2 CONFIDENTIALITY
• Symmetric-Key Ciphers
• Asymmetric-Key Ciphers

3 OTHER ASPECTS OF SECURITY
• Message Integrity
• Message Authentication
• Digital Signature
• Entity Authentication
• Key Management

4 INTERNET SECURITY
• Application-Layer Security
• Transport-Layer Security
• Network-Layer Security

5 FIREWALLS
• Packet-Filter Firewall
• Proxy Firewall

PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE

1. In the digital signature technique when the whole message is signed using an asymmetric key, the receiver of the message uses _______ to verify the signature.

• her or his own public key
• her or his own private key
• the sender's public key
• None of the choices are correct.

C. the sender's public key

2. A _______ is a trusted third party that solves the problem of symmetric-key distribution.

• CA
• KDC
• TLS
• firewall

B. KDC

3. A _______ certifies the binding between a public key and its owner.

• CA
• KDC
• TLS
• None of the choices are correct.

A. CA

4. VPN technology uses two simultaneous techniques to guarantee privacy for an organization: ________ and ___________.

• SSL; tunneling
• IPSec; SSL
• IPSec; tunneling
• None of the choices are correct.

C. IPSec; tunneling

5. IP Security (IPSec) is a collection of protocols designed by the IETF (Internet Engineering Task Force) to provide security for a packet at the _________ level.

• data link
• network
• transport
• None of the choices are correct.

B. network

6. IPSec requires a logical connection between two hosts using a signaling protocol called ____________.

• AS
• SA
• AS
• None of the choices are correct.

B. SA

7. IPSec operates at two different modes: _________ mode and _________ mode.

• transport; network
• transport; tunnel
• tunnel; surface
• None of the choices are correct.

B. transport; tunnel

8. In the _________ mode, the IPSec header is added between the IP header and the rest of the packet.

• transport
• tunnel
• transition
• None of the choices are correct.

A. transport

9. In the ________ mode, the IPSec header is placed in front of the original IP header.

• transport
• tunnel
• transition
• None of the choices are correct.

B. tunnel

10. IPSec defines two protocols: _________ and __________.

• AH: SSP
• ESP; SSP
• AH: EH
• None of the choices are correct.

D. None of the choices are correct.

11. The ________ protocol is designed to authenticate the source host and to ensure the integrity of the payload carried by the IP packet.

• AH
• ESP
• SPE
• None of the choices are correct.

A. AH

12. The _______ protocol provides message authentication and integrity, but not privacy.

• AH
• ESP
• SPE
• None of the choices are correct.

A. AH

13. The _______ protocol provides message authentication, integrity, and privacy.

• AH
• ESP
• SPE
• None of the choices are correct.

B. ESP

14. The _______ was designed to provide security at the transport layer.

• AH
• ESP
• TLS
• None of the choices are correct.

C. TLS

15. _______ was invented by Phil Zimmermann to provide all four aspects of security in the sending of email.

• AH
• ESP
• TLS
• None of the choices are correct.

D. None of the choices are correct.

16. A packet-filter firewall filters at the ________ or ___________ layer.

• network; application
• transport; application
• network; transport
• None of the choices are correct

C. network; transport

17. A proxy firewall filters at the __________ layer.

• transport
• network
• application
• None of the choices are correct.

C. application

18. Three security goals are _______________________________________.

• confidentiality, cryptography, and nonrepudiation
• confidentiality, encryption, and decryption
• confidentiality, integrity, and availability
• None of the choices are correct.

C. confidentiality, integrity, and availability

19. Which of the following attacks is threatening integrity?

• Masquerading
• Traffic Analysis
• Denial of service
• None of the choices are correct.

A. Masquerading

20. Which of the following attacks is threatening availability?

• Replaying
• Modification
• Denial of service
• None of the choices are correct.

C. Denial of service

21. _____________ means concealing the contents of a message by enciphering.

• Steganography
• Cryptography
• Compressing
• None of the choices are correct.

B. Cryptography

22. ______________ means concealing the message by covering it with something else.

• Cryptography
• Steganography
• Compressing
• None of the choices are correct.

B. Steganography

23. In __________ cryptography, the same key is used by the sender and the receiver.

• symmetric-key
• asymmetric-key
• public-key
• None of the choices are correct.

A. symmetric-key

24. In _________ cryptography, the same key is used in both directions.

• symmetric-key
• asymmetric-key
• public-key
• None of the choices are correct.

A. symmetric-key

25. _________ cryptography is often used for long messages.

• Symmetric-key
• Asymmetric-key
• public-key
• None of the choices are correct.

A. Symmetric-key

26. ___________ cryptography is often used for short messages.

• Symmetric-key
• Asymmetric-key
• Secret-key
• None of the choices are correct

B. Asymmetric-key

27. __________ means that the sender and the receiver expect confidentiality.

• Nonrepudiation
• Integrity
• Authentication
• None of the choices are correct.

D. None of the choices are correct.

28. ___________ means that the data must arrive at the receiver exactly as they were sent.

• Nonrepudiation
• Message integrity
• Authentication
• None of the choices are correct.

B. Message integrity

29. ______________ can provide authentication, integrity, and nonrepudiation for a message.

• Encryption/decryption
• Digital signature
• Compression
• None of the choices are correct.

B. Digital signature

30. Digital signature does not provide _________.

• nonrepudiation
• privacy
• authentication
• Provides all of the choices.

B. privacy

31. In ___________, the identity of a party is verified once for the entire duration of system access.

• entity authentication
• message integrity
• message authentication
• None of the choices are correct.

A. entity authentication

32. In __________ cryptography, everyone has access to everyone's public key.

• symmetric-key
• asymmetric-key
• secret-key
• None of the choices are correct.

B. asymmetric-key

33. After a message is encrypted, it is called _______.

• plaintext
• ciphertext
• cryptotext
• None of the choices are correct.

B. ciphertext

34. In the asymmetric-key method used for confidentiality, which key is publicly known?

• encryption key only
• decryption key only
• both keys
• None of the choices are correct.

B. decryption key only

35. In the asymmetric-key method used for confidentiality, the receiver uses his/her own ______________ to decrypt the message.

• private key
• public key
• no key
• None of the choices are correct.

B. public key

36. The RSA algorithm for confidentiality uses _______ cryptography.

• asymmetric-key
• symmetric-key
• substitution
• None of the choices are correct.

A. asymmetric-key

37. In RSA, if user A wants to send an encrypted message to user B, the plaintext is encrypted with the public key of _______.

• user A
• user B
• the network
• None of the choices are correct.

B. user B

38. In the digital signature technique when the whole message is signed using an asymmetric key, the sender of the message uses _______ to sign the message.

• his or her own symmetric key
• his or her own private key
• his or her own public key
• None of the choices are correct.

B. his or her own private key