Oib Part3

50 Questions | Total Attempts: 70

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Computer Network Quizzes & Trivia

Questions and Answers
  • 1. 
    A form of active wiretapping attack in which the attacker intercepts and selectively modifies communicated data in order to masquerade as one or more of the entities involved in a communication
    • A. 

      Man-in-the-middle attack

    • B. 

      A) Mandatory access control b) Intrusion detection system c) Meet-in-the-middle attack d) None of the statements a) Mandatory access control b) Intrusion detection system c) Meet-in-the-middle attack d) None of the statements Mandatory access control

    • C. 

      Intrusion detection system

    • D. 

      Meet-in-the-middle attack

    • E. 

      None of the statements

  • 2. 
    To figure out the password by trying possible likely passwords from a list is called
    • A. 

      Password attack

    • B. 

      Brute force attack

    • C. 

      Word list attack

    • D. 

      Dictionary attack

    • E. 

      Keystroke attack

  • 3. 
    To figure out the password by trying every possible keystroke combination is called
    • A. 

      Password attack

    • B. 

      Word list attack

    • C. 

      Keystroke attack

    • D. 

      Dictionary attack

    • E. 

      Brute force attack

  • 4. 
    Suppose that your plaintext is 228 bytes long and you are using RC4, how many bytes are needed for padding
    • A. 

      RC4 does not need padding

    • B. 

      Depends on the size of the block

    • C. 

      4

    • D. 

      8

    • E. 

      6

  • 5. 
    The algorithm developed by Feistel at IBM in the early 1970s and later adopted as a U.S. Federal Information Processing Standard for encrypting unclassified information is known as
    • A. 

      Digital Cipher Standard

    • B. 

      Digital Encryption Standard

    • C. 

      Data Encryption Standard

    • D. 

      Digital Cryptography Standard

    • E. 

      Data Cryptography Standard

  • 6. 
    Indicate the definition for Revocation
    • A. 

      Providing an entity with the legal right to use or transfer a resource to others

    • B. 

      Concealing the identity of an entity involved in some process

    • C. 

      Acknowledgement that services have been provided

    • D. 

      Retraction of certification or authorisation

    • E. 

      Preventing the denial of previous commitments or actions

  • 7. 
    Encrypt the message MUSTSE with the key "largest" using the Playfair cipher
  • 8. 
    In Feistel Cipher an iterated cipher with an internal function called a ___________ functio
    • A. 

      Floor

    • B. 

      Scheme

    • C. 

      Round

    • D. 

      Ceil

    • E. 

      Iteration

  • 9. 
    Indicate the definition for Witnessing
    • A. 

      Providing an entity with the legal right to use or transfer a resource to others

    • B. 

      Verifying the creation or existence of information by an entity other than the creator

    • C. 

      Acknowledgement that services have been provided

    • D. 

      Acknowledgement that information has been received

    • E. 

      Concealing the identity of an entity involved in some process

  • 10. 
    The word “asymmetric” in public-key cryptography means
    • A. 

      The key to encrypt is different from the key to decrypt

    • B. 

      The key to encrypt is the same with the key to decrypt

    • C. 

      The algorithm to encrypt is the same with the algorithm to decrypt

    • D. 

      None of the listed answers

    • E. 

      The algorithm to encrypt is different from the algorithm to decrypt

  • 11. 
    In cryptography, the original message before encryption is called
    • A. 

      Plaintext

    • B. 

      Ciphertext

    • C. 

      Cleartext

    • D. 

      Originaltext

    • E. 

      Messagetext

  • 12. 
    A general cipher design principle, not a specific cipher used by most block ciphers
    • A. 

      AES

    • B. 

      RC4

    • C. 

      DES

    • D. 

      Feistel Cipher

    • E. 

      A5/1

  • 13. 
    Indicate the definition for Non-repudiation
    • A. 

      Retraction of certification or authorisation

    • B. 

      Concealing the identity of an entity involved in some process

    • C. 

      Preventing the denial of previous commitments or actions

    • D. 

      Providing an entity with the legal right to use or transfer a resource to others

    • E. 

      Acknowledgement that services have been provided

  • 14. 
    How many possible keys does the Playfair cipher have? Ignore the fact that some keys might produce identical encryption results
    • A. 

      25

    • B. 

      26

    • C. 

      26!

    • D. 

      625

    • E. 

      25!

  • 15. 
    Why is it that the one-time pad can only be used once
    • A. 

      All of the statements

    • B. 

      If two messages encrypted with the same “one-time” pad key the probability of leaking the key is high

    • C. 

      If two messages encrypted with the same “one-time” pad key and when two different ciphertexts XORed with each other the key disappears

    • D. 

      If two messages encrypted with the same “one-time” pad key and when two different ciphertexts XORed with each other the plaintext disappears

    • E. 

      Two messages encrypted with the same “one-time” pad key the produced ciphertext always will be the same

  • 16. 
    Set of tools for generating new viruses automatically is known as a( n ) _____________
    • A. 

      Exploits

    • B. 

      Flooders

    • C. 

      Kit (virus generator)

    • D. 

      Auto-rooter

    • E. 

      Downloaders

  • 17. 
    Which of the followings are drawbacks of OTP
    • A. 

      OTP is highly secure algorithm

    • B. 

      Pad must be securely transmitted to the recipient before the ciphertext can be decrypted.

    • C. 

      A pad (key) consisting of a randomly selected string of bits that is the same length as the message.

    • D. 

      The pad (key) is the same length as the message

    • E. 

      Or modern high data-rate systems, a one-time pad cipher is totally impractical

  • 18. 
    Which malicious program Captures keystrokes on a compromised system
    • A. 

      Zombie

    • B. 

      Trojan horse

    • C. 

      Spammer

    • D. 

      Keylogger

    • E. 

      Rootkit

  • 19. 
    Code specific to a single vulnerability or set of vulnerabilities is known as a( n ) _____________
    • A. 

      Kit (virus generator)

    • B. 

      Exploits

    • C. 

      Downloaders

    • D. 

      Flooders

    • E. 

      Auto-rooter

  • 20. 
    Which software prevents Trojan horses from entering the system through back door
    • A. 

      Virus

    • B. 

      Trapdoor

    • C. 

      Firewall

    • D. 

      Cache

    • E. 

      Worm

  • 21. 
    A secret data value, usually a character string, that is used as authentication information
    • A. 

      Plaintext

    • B. 

      Public key

    • C. 

      Password

    • D. 

      Secret key

    • E. 

      Private key

  • 22. 
    Which of the following statement is NOT TRUE
    • A. 

      Any password the brute force attack tries, the dictionary attack also tries

    • B. 

      The dictionary attack tries fewer passwords than does the brute force attack

    • C. 

      The dictionary attack is faster than the brute force attack

    • D. 

      The brute-force attack tries many additional passwords that the dictionary attack does not

    • E. 

      A hacker probably start with a dictionary attack and if that fails, move on to a modified brute force attack

  • 23. 
    Which of the following are examples of the host independent malicious programs
    • A. 

      Trap door

    • B. 

      Logic Bombs

    • C. 

      Zombie

    • D. 

      Worm

    • E. 

      Trojan Horses

  • 24. 
    Which of the following statement is NOT TRUE regarding key recovery via threshold schemes
    • A. 

      If one of the trustees leaves the company, the secret is still safe, and there’s no need to restart the key recovery process from the beginning

    • B. 

      If one trustee leaves the company, his or her share becomes invalid

    • C. 

      No one person can recover keys; it takes a group acting together

    • D. 

      If one of the trustees is unavailable, it’s still possible to perform the operation

    • E. 

      The threshold scheme has many advantages over other key recovery programs

  • 25. 
    Which of these is NOT a recommended guideline for a good password
    • A. 

      Avoid using personal information

    • B. 

      Avoid using actual words

    • C. 

      Memorise it

    • D. 

      Do not write it down

    • E. 

      Store the password in a safe place