Question: Which wireless cellular security standard uses either A5/1 or A5/2 stream ciphers for encrypted communications?

Answer Choices:
A. GSM
B. VPN
C. WEP
D. WPA

Answer: A – GSM

 

 

Question: Which result does 1010 XOR 0101 return?

Answer Choices:
A. 0000
B. 0011
C. 1100
D. 1111

Answer: D – 1111

 

 

Question: What does a brute-force attack to break encryption involve?

Answer Choices:
A. Interfering between two parties and sometimes intercepting or modifying data in the communication stream
B. Analyzing ciphertext to identify text variation and comparing the text to standard English characters
C. Performing an exhaustive search to attempt every possible mapping or key
D. Identifying part of the ciphertext and the corresponding plaintext

Answer: C – Performing an exhaustive search to attempt every possible mapping or key

 

 

Question: Which symmetric encryption technique uses a 112-bit key size and a 64-bit block size?

Answer Choices:
A. AES
B. 3DES
C. IDEA
D. DES

Answer: B – 3DES

 

 

Question: What is 53 mod 11?

Answer Choices:
A. 0
B. 4
C. 5
D. 9

Answer: D – 9

 

 

Question: Employee B sends Employee A a signed message. What does Employee A use to verify the digital signature of the message?

Answer Choices:
A. Employee B’s public key
B. Employee A’s private key
C. Employee B’s private key
D. Employee A’s public key

Answer: A – Employee B’s public key

 

 

Question: Which type of exploit involves looking for similar documents that generate the same hash?

Answer Choices:
A. Birthday attack
B. Differential cryptanalysis
C. Algebraic attack
D. Linear cryptanalysis

Answer: A – Birthday attack

 

 

Question: What makes RC4 cipher unique compared to RC5 and RC6?

Answer Choices:
A. Block
B. Stream
C. Asymmetric
D. Symmetric

Answer: B – Stream

 

 

Question: Employee B wants to exchange a session key with Employee A. Which key is used to encrypt the session key?

Answer Choices:
A. Employee A’s public key
B. Employee B’s public key
C. Employee B’s private key
D. Employee A’s private key

Answer: A – Employee A’s public key

 

 

Question: What is used to confidentially exchange a session key?

Answer Choices:
A. Signature
B. Hashing
C. Symmetric encryption
D. Asymmetric encryption

Answer: D – Asymmetric encryption

 

 

Question: How does CFB mode encryption function?

Answer Choices:
A. Uses a self-synchronizing stream where the initialization vector (IV) is encrypted and XORed with the data stream one bit at a time
B. Encrypts each block with the same key, where each block is independent of the others
C. Uses an initialization vector (IV) to encrypt the first block, then uses the result of the encryption to encrypt the next block
D. Converts from block to stream, then uses a counter value and a nonce to encrypt the data

Answer: A – Uses a self-synchronizing stream where the IV is encrypted and XORed with the data stream one bit at a time

 

 

Question: What do RC4 and AES have in common?

Answer Choices:
A. Both use block encryption
B. Both use stream encryption
C. Both use asymmetric encryption
D. Both use symmetric encryption

Answer: D – Both use symmetric encryption

 

 

Question: Employee A needs to send Employee B a symmetric key for confidential communication. Which key is needed to decrypt the symmetric key?

Answer Choices:
A. Employee A’s public key
B. Employee A’s private key
C. Employee B’s public key
D. Employee B’s private key

Answer: D – Employee B’s private key

 

 

Question: Which key is used to decrypt a hash in a digitally signed message?

Answer Choices:
A. Sender’s private key
B. Recipient’s private key
C. Recipient’s public key
D. Sender’s public key

Answer: D – Sender’s public key