This is the MCQs in Cryptography from book the Data Communications and Networking 4th Edition by Behrouz A. Forouzan. If you are looking for a reviewer in Electronics Systems and Technologies (Communications Engineering) this will definitely help you before taking the Board Exam.
Topic Outline
- INTRODUCTION
- Definitions
- Two Categories
- SYMMETRIC-KEY CRYPTOGRAPHY
- Traditional Ciphers
- Simple Modem Ciphers
- Modern Round Ciphers
- Mode of Operation
- ASYMMETRIC-KEY CRYPTOGRAPHY
- RSA
- Diffie-Hellman
Begin and Good luck!
Choose the letter of the best answer in each questions.
1. One commonly used public-key cryptography method is the ______ algorithm.
- A) RSS
- B) RAS
- C) RSA
- D) RAA
2. A(n) ______ algorithm transforms ciphertext to plaintext.
- A) encryption
- B) decryption
- C) either (a) or (b)
- D) neither (a) nor (b)
3. The ________ is the message after transformation.
- A) ciphertext
- B) plaintext
- C) secret-text
- D) none of the above
4. A(n) _______ algorithm transforms plaintext to ciphertext.
- A) encryption
- B) decryption
- C) either (a) or (b)
- D) neither (a) nor (b)
5. The ________ method provides a one-time session key for two parties.
- A) Diffie-Hellman
- B) RSA
- C) DES
- D) AES
6. A(n) ______ is a keyless substitution cipher with N inputs and M outputs that uses a formula to define the relationship between the input stream and the output stream.
- A) S-box
- B) P-box
- C) T-box
- D) none of the above
7. A ________ cipher replaces one character with another character.
- A) substitution
- B) transposition
- C) either (a) or (b)
- D) neither (a) nor (b)
8. The ________ cipher reorders the plaintext characters to create a ciphertext.
- A) substitution
- B) transposition
- C) either (a) or (b)
- D) neither (a) nor (b)
9. _______ is a round cipher based on the Rijndael algorithm that uses a 128-bit block of data.
- A) AEE
- B) AED
- C) AER
- D) AES
10. The ________is the original message before transformation.
- A) ciphertext
- B) plaintext
- C) secret-text
- D) none of the above
11. A modern cipher is usually a complex _____cipher made of a combination of different simple ciphers.
- A) round
- B) circle
- C) square
- D) none of the above
12. The _________ attack can endanger the security of the Diffie-Hellman method if two parties are not authenticated to each other.
- A) man-in-the-middle
- B) ciphertext attack
- C) plaintext attack
- D) none of the above
13. A combination of an encryption algorithm and a decryption algorithm is called a ________.
- A) cipher
- B) secret
- C) key
- D) none of the above
14. In an asymmetric-key cipher, the receiver uses the ______ key.
- A) private
- B) public
- C) either a or b
- D) neither (a) nor (b)
15. AES has _____ different configurations.
- A) two
- B) three
- C) four
- D) five
16. DES is a(n) ________ method adopted by the U.S. government.
- A) symmetric-key
- B) asymmetric-key
- C) either (a) or (b)
- D) neither (a) nor (b)
17. DES uses a key generator to generate sixteen _______ round keys.
- A) 32-bit
- B) 48-bit
- C) 54-bit
- D) 42-bit
18. The Caesar cipher is a _______cipher that has a key of 3.
- A) transposition
- B) additive
- C) shift
- D) none of the above
19. ECB and CBC are ________ ciphers.
- A) block
- B) stream
- C) field
- D) none of the above
20. A(n) _______is a keyless transposition cipher with N inputs and M outputs that uses a table to define the relationship between the input stream and the output stream.
- A) S-box
- B) P-box
- C) T-box
- D) none of the above
21. ________ DES was designed to increase the size of the DES key.
- A) Double
- B) Triple
- C) Quadruple
- D) none of the above
22. ________ is the science and art of transforming messages to make them secure and immune to attacks.
- A) Cryptography
- B) Cryptoanalysis
- C) either (a) or (b)
- D) neither (a) nor (b)
23. DES has an initial and final permutation block and _________ rounds.
- A) 14
- B) 15
- C) 16
- D) none of the above
24. The DES function has _______ components.
- A) 2
- B) 3
- C) 4
- D) 5
25. In a(n) ________ cipher, the same key is used by both the sender and receiver.
- A) symmetric-key
- B) asymmetric-key
- C) either (a) or (b)
- D) neither (a) nor (b)
26. _________ ciphers can be categorized into two broad categories: monoalphabetic and polyalphabetic.
- A) Substitution
- B) Transposition
- C) either (a) or (b)
- D) neither (a) nor (b)
27. The _______ cipher is the simplest monoalphabetic cipher. It uses modular arithmetic with a modulus of 26.
- A) transposition
- B) additive
- C) shift
- D) none of the above
28. In an asymmetric-key cipher, the sender uses the__________ key.
- A) private
- B) public
- C) either (a) or (b)
- D) neither (a) nor (b)
29. In a(n) ________ cipher, a pair of keys is used.
- A) symmetric-key
- B) asymmetric-key
- C) either (a) or (b)
- D) neither (a) nor (b)
30. The _______ is a number or a set of numbers on which the cipher operates.
- A) cipher
- B) secret
- C) key
- D) none of the above
31. In a(n) ________, the key is called the secret key.
- A) symmetric-key
- B) asymmetric-key
- C) either (a) or (b)
- D) neither (a) nor (b)
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