Substitution and Transposition Techniques MCQ

Test your knowledge with important Substitution and Transposition Techniques MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Substitution and Transposition Techniques MCQs at Bissoy

• A symmetric cipher system has an IC of 0.041. What is the length of the key ‘m’?
  ক

  1

  খ

  3

  গ

  2

  ঘ

  5
• Consider the cipher text message with relative frequencies: 4 0 10 25 5 32 24 15 6 11 5 5 1 2 6 6 15 19 10 0 6 28 8 2 3 2 The Index of Coincidence is
  ক

  0.065

  খ

  0.048

  গ

  0.067

  ঘ

  0.042
• If all letters have the same chance of being chosen, the IC is approximately
  ক

  0.065

  খ

  0.035

  গ

  0.048

  ঘ

  0.038
• The Index of Coincidence for English language is approximately
  ক

  0.068

  খ

  0.038

  গ

  0.065

  ঘ

  0.048
• On Encrypting “cryptography” using Vignere Cipher System using the keyword “LUCKY” we get cipher text
  ক

  nlazeiibljji

  খ

  nlazeiibljii

  গ

  olaaeiibljki

  ঘ

  mlaaeiibljki
• On Encrypting “thepepsiisintherefrigerator” using Vignere Cipher System using the keyword “HUMOR” we get cipher text-
  ক

  abqdnwewuwjphfvrrtrfznsdokvl

  খ

  abqdvmwuwjphfvvyyrfznydokvl

  গ

  tbqyrvmwuwjphfvvyyrfznydokvl

  ঘ

  baiuvmwuwjphfoeiyrfznydokvl
• Choose from among the following cipher systems, from best to the worst, with respect to ease of decryption using frequency analysis.
  ক

  Random Polyalphabetic, Plaintext, Playfair

  খ

  Random Polyalphabetic, Playfair, Vignere

  গ

  Random Polyalphabetic, Vignere, Playfair, Plaintext

  ঘ

  Random Polyalphabetic, Plaintext, Beaufort, Playfair
• Which are the most frequently found letters in the English language ?
  ক

  e,a

  খ

  e,o

  গ

  e,t

  ঘ

  e,i
• Monoalphabetic ciphers are stronger than Polyalphabetic ciphers because frequency analysis is tougher on the former.
  ক

  True

  খ

  False
• Caesar Cipher is an example of
  ক

  Poly-alphabetic Cipher

  খ

  Mono-alphabetic Cipher

  গ

  Multi-alphabetic Cipher

  ঘ

  Bi-alphabetic Cipher
• Use Caesar’s Cipher to decipher the following HQFUBSWHG WHAW
  ক

  ABANDONED LOCK

  খ

  ENCRYPTED TEXT

  গ

  ABANDONED TEXT

  ঘ

  ENCRYPTED LOCK