Module 9 - Application of Cryptographic Methods - Q&A

Question 1

Which type of algorithm is typically used to encrypt data-at-rest?
A. Symmetric
B. Asymmetric
C. Streaming
D. Block

Answer 1

A. Symmetric algorithms are typically used to encrypt data in storage.

Question 2

Which of the following security protocols is used by HTTPS? (Choose two.)
A. SSL
B. AES
C. TLS
D. SSH

Answer 2

A, C. HTTPS uses either SSL or TLS transmission security protocols.

Question 3

Which of the following security protocols can be used either between two hosts or two untrusted networks in order to secure traffic?
A. AES
B. IPsec
C. DES
D. Twofish

Answer 3

B. IPsec is a transmission security protocol that can be used either between two local hosts or between two untrusted networks.

Question 4

Which of the following wireless security protocols introduced the Temporal Key Integrity protocol to provide better security services?
A. TLS
B. SSL
C. WEP
D. WPA

Answer 4

D. WPA introduced TKIP in order to compensate for deficiencies found in WEP and RC4.

Question 5

Which of the following types of bits does steganography use to conceal data?
A. Leftmost bit
B. High order bit
C. Most significant bit
D. Least significant bit

Answer 5

D. Steganography typically modifies the least significant bit in a byte in order to conceal data.

Question 6

Which of the following places secrecy of the key versus secrecy of the algorithm as the most important factor in developing secure and reliable cryptosystems?
A. The Data Encryption Standard (DES)
B. The Advanced Encryption Standard (AES)
C. Kerckhoffs’s principle
D. The Digital Signature Algorithm (DSA)

Answer 6

C. Kerckhoffs’s principle states that reliable cryptosystems should depend upon the secrecy of the key, rather than the secrecy of the algorithm.

Question 7

All of the following factors are considerations in selecting strong versus weak algorithms, except:
A. Mode
B. Speed and efficiency
C. Key length and space
D. Mathematical algorithm

Answer 7

B. Speed and efficiency are not factors in selecting strong algorithms over weak algorithms.

Question 8

Which of the following is a method of strengthening weak keys by exposing them either to more complex modes or multiple rounds of encryption?
A. Key stretching
B. Confusion
C. Diffusion
D. Perfect forward secrecy

Answer 8

A. Key stretching is a method used to strengthen weaker keys by exposing them to more rounds of encryption or more complex modes.

Question 9

Which of the following is a characteristic of ephemeral keys?
A. Used only as many times as there are rounds for a particular algorithm
B. Increases diffusion
C. Used only once, immediately after generation
D. Decreases diffusion

Answer 9

C. Ephemeral keys are used only once, immediately after generation, and are never used again.

Question 10

Which of the following concepts is described as the inability to compromise a generated key, even if the original key is compromised?
A. Ephemeral keys
B. Perfect forward secrecy
C. Confusion
D. Diffusion Answers

Answer 10

B. Perfect forward secrecy is a concept found in public key cryptography that states that even if an original key is compromised, derivative keys generated from it cannot be compromised.