51. Which one of the following is used in banks, business and networks all over the world for security aspects?

(a) AES
(b) DES
(c) RSA
(d) NIST

Answer: (b)

52. IDEA stands for:
(a) Information Digital Encryption Agency
(b) International Digital Encryption Algorithm
(c) Information Data Encryption Agency
(d) International Data Encryption Algorithm

Answer: (d)

53. Pretty Good Privacy (PGP) is a cryptosystem intended for use of:
(a) Voice security
(b) E-mail security
(c) Internet security
(d) Bank security

Answer: (b)

54. Microsoft cryptographic providers support three hash algorithms are:

Answer: (b)

55. S/MIME stands for:
(a) Secure Mobile Internet Mail Extension
(b) Service Mobile Internet Multipurpose Extension
(c) System Multipurpose Internet Mobile Extension
(d) Secure Multipurpose Internet Mail Extension

Answer: (d)

56. Biometric characteristics cannot be directly used as cryptographic key, because biometric images are:
(a) Difficult to obtain
(b) Difficult to process
(c) Difficult to recognize
(d) Variable by nature

Answer: (d)

57. The operations performed in AES algorithm for each round are:
1. Substitute bytes
2. Shift columns
3. Mix rows
4. Add round key

(a) 1 and 4 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 2 and 4 only

Answer: (a)

58. A stream cipher is designed to operate:
(a) On a block of plain text
(b) One bit or units larger than a byte at a time
(c) One that has a sequence of rounds
(d) One block of data at a time

Answer: (b)

59. In the Cipher Block Chaining (CBC) mode, the input to the encryption algorithm is:
(a) The each plain text block encoded using same key
(b) The each plain text block encoded using different key
(c) The XOR of the current plain text block and the preceding cipher text block, same key used for each block
(d) The XOR of the current plain text block and the preceding cipher text block, different key used for each block

Answer: (c)

60. Message Authentification Code (MAC) is:
(a) Accepting a variable size message M as input and producing a fixed size message digest H(M) as output
(b) Using a secret key to generate a small block of data
(c) The statistical structure of the plaintext dissipated into long range statistics of the cipher text
(d) A technique in which chosen plain texts with particular XOR difference pattern are encrypted

Answer: (a)