McqMate

42

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1. |
## In symmetric-key cryptography, the key locks and unlocks the box is |

A. | same |

B. | shared |

C. | private |

D. | public |

Answer» A. same |

2. |
## The keys used in cryptography are |

A. | secret key |

B. | private key |

C. | public key |

D. | all of them |

Answer» D. all of them |

3. |
## Cryptography, a word with Greek origins, means |

A. | corrupting data |

B. | secret writing |

C. | open writing |

D. | closed writing |

Answer» B. secret writing |

4. |
## A transposition cipher reorders (permutes) symbols in a |

A. | block of packets |

B. | block of slots |

C. | block of signals |

D. | block of symbols |

Answer» D. block of symbols |

5. |
## Network Security provides authentication and access control for resources. |

A. | true |

B. | false |

Answer» A. true |

6. |
## Which is not an objective of network security? |

A. | identification |

B. | authentication |

C. | access control |

D. | lock |

Answer» D. lock |

7. |
## The process of verifying the identity of a user. |

A. | authentication |

B. | identification |

C. | validation |

D. | verification |

Answer» A. authentication |

8. |
## Which of these is a part of network identification? |

A. | user id |

B. | password |

C. | otp |

D. | fingerprint |

Answer» A. user id |

9. |
## The process of transforming plain text into unreadable text. |

A. | decryption |

B. | encryption |

C. | network security |

D. | information hiding |

Answer» B. encryption |

10. |
## An algorithm used in encryption is referred to as cipher. |

A. | true |

B. | false |

Answer» A. true |

11. |
## A process of making the encrypted text readable again. |

A. | decryption |

B. | encryption |

C. | network security |

D. | information hiding |

Answer» A. decryption |

12. |
## A person who enjoys learning details about computers and how to enhance their capabilities. |

A. | cracker |

B. | hacker |

C. | app controller |

D. | site controller |

Answer» B. hacker |

13. |
## A small program that changes the way a computer operates. |

A. | worm |

B. | trojan |

C. | bomb |

D. | virus |

Answer» D. virus |

14. |
## An asymmetric-key (or public-key) cipher uses |

A. | 1 key |

B. | 2 key |

C. | 3 key |

D. | 4 key |

Answer» B. 2 key |

15. |
## We use cryptofraphy term to transform messages to make them secure and immune to |

A. | change |

B. | idle |

C. | attacks |

D. | defend |

Answer» C. attacks |

16. |
## In cryptography , the original message before being transformmed , is called |

A. | simple text |

B. | plain text |

C. | empty text |

D. | filled text |

Answer» B. plain text |

17. |
## A straight permutation cipher or a straight p-box has the same number of input as |

A. | cipher |

B. | frames |

C. | outputs |

D. | bits |

Answer» C. outputs |

18. |
## The man-in-the-middle attack can endanger the security of the diffie-hellman if two parties are not |

A. | authenticated |

B. | joined |

C. | submit |

D. | separate |

Answer» A. authenticated |

19. |
## Which of the following is not a transport layer vulnerability? |

A. | mishandling of undefined , poorly defined |

B. | the vulnerability that allows fingerprinting & other enumeration of host information |

C. | overloading of transporting layer mechanisms |

D. | unauthorized network access |

Answer» D. unauthorized network access |

20. |
## Transmission mechanisms can be subject to spoofing & attacks based on skilled modified packets. |

A. | true |

B. | false |

Answer» A. true |

21. |
## TCP/IP model does not have layer but OSI model have this layer. |

A. | session layer |

B. | transport layer |

C. | application layer |

D. | network layer |

Answer» A. session layer |

22. |
## In cryptography, what is cipher? |

A. | algorithm for performing encrption and decryption |

B. | encrypted message |

C. | both algorith for performing encrption and decryption and encrypted message |

D. | decrypted message |

Answer» A. algorithm for performing encrption and decryption |

23. |
## In cryptography, the order of the letters in a message is rearranged by |

A. | transpositional ciphers |

B. | substitution ciphers |

C. | both |

D. | quadratic ciphers |

Answer» A. transpositional ciphers |

24. |
## What is data encryption standard (DES)? |

A. | block cipher |

B. | stream cipher |

C. | bit cipher |

D. | byte cipher |

Answer» A. block cipher |

25. |
## Cryptanalysis is used |

A. | to find some insecurity in a cryptographic scheme |

B. | to increase the speed |

C. | to encrypt the data |

D. | to make new ciphers |

Answer» A. to find some insecurity in a cryptographic scheme |

26. |
## Choose from among the following cipher systems, from best to the worst, with respect to ease of decryption using frequency analysis. |

A. | random polyalphabetic , plaintext , playfair |

B. | random polyalphabetic , playfair , vignere |

C. | random polyalphabetic , vignere , playfair , plaintext |

D. | random polyalphabetic , plaintext , beaufort , playfair |

Answer» C. random polyalphabetic , vignere , playfair , plaintext |

27. |
## On Encrypting “thepepsiisintherefrigerator” using Vignere Cipher System using the keyword “HUMOR” we get cipher text- |

A. | abqdnwewuwjphfvrrtrfzn sdokvl |

B. | abqdvmwuwjphfvvyyrf znydokvl |

C. | tbqyrvmwuwjphfvvyy rfznydokvl |

D. | baiuvmwuwjphfoeiyrf znydokvl |

Answer» B. abqdvmwuwjphfvvyyrf znydokvl |

28. |
## . Rail Fence Technique is an example of |

A. | substitution |

B. | transposition |

C. | product cipher |

D. | ceaser cipher |

Answer» B. transposition |

29. |
## Public key encryption is advantageous over Symmetric key Cryptography because of |

A. | speed |

B. | space |

C. | key exchange |

D. | key length |

Answer» C. key exchange |

30. |
## The sub key length at each round of DES is |

A. | 32 |

B. | 56 |

C. | 48 |

D. | 64 |

Answer» B. 56 |

31. |
## Which one is the strong attack mechanism? |

A. | chosen plaintext attack |

B. | chosen cipher text |

C. | brute force attack |

D. | man in the middle attack |

Answer» C. brute force attack |

32. |
## Interception is an attack on |

A. | availability |

B. | confidentiality |

C. | integrity |

D. | authenticity |

Answer» B. confidentiality |

33. |
## Chosen cipher text attack is based on |

A. | cryptanalysis |

B. | cryptography |

C. | encryption |

D. | decryption |

Answer» A. cryptanalysis |

34. |
## The process of writing the text as rows and read it as columns is known as |

A. | vernam cipher |

B. | ceaser cipher |

C. | transposition columnar cipher |

D. | homophonic substitution cipher |

Answer» C. transposition columnar cipher |

35. |
## Biometric authentication works on the basis of |

A. | human characteristics |

B. | passwords |

C. | smart cards |

D. | pin |

Answer» A. human characteristics |

36. |
## Which layer filters the proxy firewall? |

A. | application |

B. | network |

C. | transport |

D. | none of the above |

Answer» A. application |

37. |
## Encryption Strength is based on |

A. | strength of algorithm |

B. | secrecy of key |

C. | length of key |

D. | all of the above |

Answer» D. all of the above |

38. |
## GCD(a,b) = GCD(b,a mod b) |

A. | true |

B. | false |

C. | cannot be determined |

D. | none |

Answer» A. true |

39. |
## All groups satisfy properties |

A. | g-i to g-v |

B. | g-i to g-iv |

C. | g-i to r-v |

D. | r-i to r-v |

Answer» C. g-i to r-v |

40. |
## An Abelian Group satisfies the properties |

A. | g-i to g-v |

B. | g-i to g-iv |

C. | g-i to r-v |

D. | r-i to r-v |

Answer» A. g-i to g-v |

41. |
## A Ring satisfies the properties |

A. | r-i to r-v |

B. | g-i to g-iv |

C. | g-i to r-v |

D. | g-i to r-iii |

Answer» D. g-i to r-iii |

42. |
## A Ring is said to be commutative if it also satisfies the property |

A. | r-vi |

B. | r-v |

C. | r-vii |

D. | r-iv |

Answer» D. r-iv |

43. |
## An ‘Integral Domain’ satisfies the properties |

A. | g-i to g-iii |

B. | g-i to r-v |

C. | g-i to r-vi |

D. | g-i to r-iii |

Answer» C. g-i to r-vi |

44. |
## Does the set of residue classes (mod 3) form a group with respect to modular addition? |

A. | yes |

B. | no |

C. | can\t say |

D. | insufficient data |

Answer» A. yes |

45. |
## For the group Sn of all permutations of n distinct symbols, what is the number of elements in Sn? |

A. | n |

B. | n-1 |

C. | 2n |

D. | n! |

Answer» D. n! |

46. |
## a(b+c) = ac+bc is the representation for which property? |

A. | g-ii |

B. | g-iii |

C. | r-ii |

D. | r-iii |

Answer» D. r-iii |

47. |
## a.(b.c) = (a.b).c is the representation for which property? |

A. | g-ii |

B. | g-iii |

C. | r-ii |

D. | r-iii |

Answer» A. g-ii |

48. |
## AES uses a bit block size and a key size of bits. |

A. | 128; 128 or 256 |

B. | 64; 128 or 192 |

C. | 256; 128, 192, or 256 |

D. | 128; 128, 192, or 256 |

Answer» D. 128; 128, 192, or 256 |

49. |
## Like DES, AES also uses Feistel Structure. |

A. | true |

B. | false |

C. | cannot be determined |

D. | none |

Answer» B. false |

50. |
## Which one of the following is not a cryptographic algorithm? |

A. | jupiter |

B. | blowfish |

C. | serpent |

D. | none |

Answer» A. jupiter |

51. |
## If the key is 110100001, the output of the SP network for the plaintext: 101110001 is |

A. | 110100011 |

B. | 110101110 |

C. | 10110111 |

D. | 11111010 |

Answer» B. 110101110 |

52. |
## What is the number of possible 3 x 3 affine cipher transformations |

A. | 168 |

B. | 840 |

C. | 1024 |

D. | 1344 |

Answer» D. 1344 |

53. |
## What is the expanded key size of AES-192? |

A. | 44 words |

B. | 60 words |

C. | 52 words |

D. | 36 words |

Answer» C. 52 words |

54. |
## In affine block cipher systems if f(m)=Am + t, what is f(m1+m2+m3) ? |

A. | f(m1) + f(m2) + f(m3) + t |

B. | f(m1) + f(m2) + f(m3) +2t |

C. | f(m1) + f(m2) + f(m3) |

D. | 2(f(m1) + f(m2) + f(m3)) |

Answer» C. f(m1) + f(m2) + f(m3) |

55. |
## The 4×4 byte matrices in the AES algorithm are called |

A. | states |

B. | words |

C. | transitions |

D. | permutations |

Answer» A. states |

56. |
## If the block size is ‘s’, how many affine transformations are possible ? |

A. | 2s (2s-1)(2s-1)(2s-12) ………(2s-1(s-1)) |

B. | 2s (2s-1)(2s-2)(2s-22) ………(2s-2(s-2)) |

C. | 2ss (2s-1)(2s-2)(2s-22) ………(2s-2(s-1)) |

D. | 2s (2s-1)(2s-2)(2s-22) ………(2s-2(s-3)) |

Answer» C. 2ss (2s-1)(2s-2)(2s-22) ………(2s-2(s-1)) |

57. |
## For the AES-128 algorithm there are similar rounds and round is different. |

A. | 2 pair of 5 similar rounds ; every alternate |

B. | 9 ; the last |

C. | 8 ; the first and last |

D. | 10 ; no |

Answer» B. 9 ; the last |

58. |
## The DES Algorithm Cipher System consists of rounds (iterations) each with a round key |

A. | 9 |

B. | 12 |

C. | 18 |

D. | 16 |

Answer» D. 16 |

59. |
## DES follows |

A. | hash algorithm |

B. | caesars cipher |

C. | feistel cipher structure |

D. | sp networks |

Answer» C. feistel cipher structure |

60. |
## Every cyclic group is . |

A. | a group with finite order |

B. | a group with prime order |

C. | a non abelian group |

D. | an abelian group |

Answer» D. an abelian group |

61. |
## In the DES algorithm the round key is bit and the Round Input is bits |

A. | 48, 32 |

B. | 64,32 |

C. | 56, 24 |

D. | 32, 32 |

Answer» A. 48, 32 |

62. |
## is not a binary operation on the set of natural numbers. |

A. | addition |

B. | product |

C. | difference |

D. | none |

Answer» C. difference |

63. |
## In the DES algorithm the Round Input is 32 bits, which is expanded to 48 bits via |

A. | scaling of the existing bits |

B. | duplication of the existing bits |

C. | addition of zeros |

D. | addition of ones |

Answer» A. scaling of the existing bits |

64. |
## Which of the following is group under multiplication? |

A. | q |

B. | q-{0} |

C. | q-{1} |

D. | q-{0,1} |

Answer» B. q-{0} |

65. |
## The Initial Permutation table/matrix is of size |

A. | 16×8 |

B. | 4×8 |

C. | 12×8 |

D. | 8×8 |

Answer» D. 8×8 |

66. |
## The number of unique substitution boxes in DES after the 48 bit XOR operation are |

A. | 8 |

B. | 4 |

C. | 6 |

D. | 12 |

Answer» A. 8 |

67. |
## The DES algorithm has a key length of |

A. | 128 bits |

B. | 32 bits |

C. | 64 bits |

D. | 16 bits |

Answer» C. 64 bits |

68. |
## What is the size of the key in the SDES algorithm? |

A. | 24 bits |

B. | 16 bits |

C. | 20 bits |

D. | 10 bits |

Answer» D. 10 bits |

69. |
## The Plaintext for the Ciphertext 10100101, given that the key is 0010010111 is |

A. | 1100111 |

B. | 110110 |

C. | 1001000 |

D. | 1001100 |

Answer» B. 110110 |

70. |
## Assume input 10-bit key, K: 1010000010 for the SDES algorithm. What is K1? |

A. | 10100100 |

B. | 1011011 |

C. | 1101000 |

D. | 10100111 |

Answer» A. 10100100 |

71. |
## Assume input 10-bit key, K: 0010010111 for the SDES algorithm. What is K2? |

A. | 11101010 |

B. | 11011011 |

C. | 1101000 |

D. | 10101111 |

Answer» A. 11101010 |

72. |
## Which of the following is a mode of operation for the Block ciphers in cryptography? |

A. | a. electronic code book (ecb) |

B. | cipher block chaining (cbc) |

C. | counter (ctr) mode |

D. | all of the above |

Answer» D. all of the above |

73. |
## Which of the following modes of operations can be followed for both stream ciphers as well as block ciphers? |

A. | a. cbc (cipher block chaining) |

B. | ecb (electronic code book) |

C. | a. cfb (cipher text feed back) |

D. | all of the above |

Answer» C. a. cfb (cipher text feed back) |

74. |
## The Plaintext for the Ciphertext 00001111, given that the key is 1111111111 is |

A. | 1100111 |

B. | 1010 |

C. | 11111111 |

D. | 1101101 |

Answer» C. 11111111 |

75. |
## Which one of the following RC4 algorithm not used in? |

A. | ssl |

B. | tls |

C. | ftp |

D. | wep |

Answer» C. ftp |

76. |
## Till when was the RC4 algorithm kept a secret? |

A. | 1990 |

B. | 1992 |

C. | 1996 |

D. | 1994 |

Answer» D. 1994 |

77. |
## The Plaintext for the Ciphertext 00100010, given that the key is 1111111111 is |

A. | 1100111 |

B. | 1010 |

C. | 1001000 |

D. | 1001100 |

Answer» D. 1001100 |

78. |
## The man-in-the-middle attack can endanger the security of the Diffie-Hellman method if two parties are not |

A. | authenticated |

B. | joined |

C. | submit |

D. | separate |

Answer» A. authenticated |

79. |
## RSA is also a stream cipher like Merkel-Hellman |

A. | true |

B. | false |

Answer» A. true |

80. |
## Rabin Cryptosystem is a variant of the Elgamal Cryptosystem |

A. | true |

B. | false |

Answer» B. false |

81. |
## In RSA, Ф(n) = in terms of p and q |

A. | (p)/(q) |

B. | (p)(q) |

C. | (p-1)(q-1) |

D. | (p+1)(q+1) |

Answer» C. (p-1)(q-1) |

82. |
## In Asymmetric Key Cryptography, the two key, e and d, have a special relationship to |

A. | others |

B. | data |

C. | keys |

D. | each other |

Answer» D. each other |

83. |
## Using Rabin cryptosystem with p=23 and q=7 ,Encrypt P=24 to find ciphertext. The Cipher text is |

A. | 42 |

B. | 93 |

C. | 74 |

D. | 12 |

Answer» D. 12 |

84. |
## For RSA to work, the value of P must be less than the value of |

A. | p |

B. | q |

C. | n |

D. | f |

Answer» C. n |

85. |
## Session keys are transmitted after being encrypted by |

A. | make-shift keys |

B. | temporary keys |

C. | master keys |

D. | section |

Answer» C. master keys |

86. |
## Which Cryptographic system uses C1 = (e1r) mod p and C1 = (e2r x P) mod p at the encryption side? |

A. | elgamal |

B. | rsa |

C. | rabin |

D. | whirlpool |

Answer» A. elgamal |

87. |
## The certificate message is required for any agreed-on key exchange method except |

A. | ephemeral diffie- hellman |

B. | anonymous diffie- hellmanc |

C. | fixed diffie- hellmand. |

D. | rsa |

Answer» B. anonymous diffie- hellmanc |

88. |
## Sender chooses p = 107, e1 = 2, d = 67, and the random integer is r=45. Find the plaintext to be transmitted if the ciphertext is (28,9) |

A. | 45 |

B. | 76 |

C. | 66 |

D. | 13 |

Answer» C. 66 |

89. |
## In Asymmetric key Cryptography, although RSA can be used to encrypt and decrypt actual messages, it is very slow if the message is |

A. | short |

B. | long |

C. | flat |

D. | thin |

Answer» B. long |

90. |
## Which of the following is not a type of symmetric-key cryptography technique? |

A. | caesar cipher |

B. | data encryption standard (des) |

C. | diffie hellman cipher |

D. | playfair cipher |

Answer» C. diffie hellman cipher |

91. |
## In Elgamal cryptosystem, given the prime p=31,Choose e1= first primitive root of p and d=10, calculate e2 |

A. | 24 |

B. | 36 |

C. | 25 |

D. | 62 |

Answer» C. 25 |

92. |
## How many bytes of the secret key is generated using Diffie-Hellman encryption/decryption scheme? |

A. | 256 |

B. | 871 |

C. | 1024 |

D. | 962 |

Answer» A. 256 |

93. |
## Computation of the discrete logarithm is the basis of the cryptographic system |

A. | symmetric cryptography |

B. | asymmetric cryptography |

C. | diffie-hellman key exchange |

D. | secret key cryptography |

Answer» C. diffie-hellman key exchange |

94. |
## In Elgamal cryptosystem, given the prime p=31,Encrypt the message “HELLO”; use 00 to 25 for encoding. The value of C2 for character ‘O’ is |

A. | 9 |

B. | 7 |

C. | 23 |

D. | 27 |

Answer» A. 9 |

95. |
## What is the block size of RC6 Feistel block cipher? |

A. | 5013 bits |

B. | 128 bits |

C. | 596 bits |

D. | 1768 bits |

Answer» B. 128 bits |

96. |
## What is the general equation for elliptic curve systems |

A. | y3+b_1 xy+b_2 y=x33+a_1 x2+a_2 x+a_3 |

B. | y3+b_1 x+b_2 y=x2+a_1 x2+a_2 x+a_3 |

C. | y2+b_1 xy+b_2 y=x3+a_1 x2+a_2 |

D. | y2+b_1 xy+b_2 y=x3+a_1 x2+a_2 x+a_3 |

Answer» D. y2+b_1 xy+b_2 y=x3+a_1 x2+a_2 x+a_3 |

97. |
## USENET falls under which category of public key sharing? |

A. | public announcement |

B. | publicly available directory |

C. | public-key authority |

D. | public-key certificates |

Answer» A. public announcement |

98. |
## In Singular elliptic curve, the equation x^3+ax+b=0 does roots |

A. | does not have three distinct |

B. | has three distinct |

C. | has three unique |

D. | has three distinct unique |

Answer» A. does not have three distinct |

99. |
## The value of 52003 mod 7 is(use fermat's theorem) |

A. | 3 |

B. | 4 |

C. | 8 |

D. | 9 |

Answer» A. 3 |

100. |
## Elliptic curve cryptography follows the associative property |

A. | true |

B. | false |

Answer» A. true |

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