Network Security

Question 11

In a RSA cryptosystem, a participant A uses two prime numbers p=13 and q=11 to generate his public and private keys. If the public key of A is 37, then the private key of A is _____.

• 18
• 23
• 11
• 13

Question 12

Which of the following are used to generate a message digest by the network security protocols? (P) SHA-256 (Q) AES (R) DES (S) MD5

• P and S only
• P and Q only
• R and S only
• P and R only

Question 13

MD5 is a widely used hash function for producing hash value of

• 64 bits
• 128 bits
• 512 bits
• 1024 bits

Question 14

Pretty Good Privacy (PGP) is used in

• Browser security
• FTP security
• Email security
• None of the above

Question 15

An attacker sits between the sender and receiver and captures the information and retransmits to the receiver after some time without altering the information. This attack is called as _____.

• Denial of service attack
• Masquarade attack
• Simple attack
• Complex attack

Question 16

In a system an RSA algorithm with p=5 and q=11, is implemented for data security. What is the value of the decryption key if the value of the encryption key is 27?

• 3
• 7
• 27
• 40

Question 17

An attacker sits between customer and Banker, and captures the information from thecustomer and retransmits to the banker by altering the information. This attack is called as ______.

• Masquerade Attack
• Replay Attack
• Passive Attack
• Denial of Service Attack

Question 18

Encrypt the plain text Message “EXTRANET” using Transposition cipher technique with the following key: Using ‘Z’ as bogus character.

• TAXERTZENZ
• EXTRANETZZ
• EZXZTRZANZET
• EXTZRANZETZ

Question 19

Which of the following encryption algorithms is based on the Fiestal structure?

• Advanced Encryption Standard
• RSA public key cryptographic algorithm
• Data Encryption Standard
• RC4

Question 20

Using p = 3, q = 13, d = 7 and e = 3 in the RSA algorithm, what is the value of ciphertext for a plain text 5 ?

• 8
• 16
• 26
• 33