WGU D830 INTRODUCTION TO CRYPTOGRAPHY OA
(OBJECTIVE ASSESSMENT) QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES NEW 2026-2027 UPDATE
100 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Analyze and differentiate symmetric and asymmetric cryptographic algorithms based on security
properties and performance characteristics
2 Evaluate cryptographic hash functions and message authentication codes for integrity, collision
resistance, and preimage resistance
3 Apply key management principles, including key exchange, distribution, and storage, to design secure
systems
4 Interpret and critique digital signatures, certificates, and PKI trust models within contemporary security
frameworks
5 Identify and mitigate common cryptographic implementation vulnerabilities and protocol flaws
6 WGU D830 Introduction to Cryptography OA
7 Objective Assessment
8 Questions and Correct Answers with Rationales New 2026
9 2027 Update
10 Foundations of Cryptography and Information Security
11 Applied Cryptography and Information Security
12 Advanced Cryptography and Information Security
13 Cryptography and Information Security Review
ABSTRACT
Page 1
,This study document brings together 100 carefully worded exam questions drawn from WGU D830
Introduction to Cryptography OA (Objective Assessment) Questions and Correct Answers with
Rationales New 2026-2027 Update, with the strongest emphasis placed on Analyze and
differentiate symmetric and asymmetric cryptographic algorithms based on security properties and
performance characteristics, Evaluate cryptographic hash functions and message authentication
codes for integrity, collision resistance, and preimage resistance, Apply key management
principles, including key exchange, distribution, and storage and to design secure systems. Every
item follows the wording style and level of reasoning you meet in the real paper, and each one is
paired with a clear rationale so the correct choice is never a guess. Work through the set at your
own pace, mark the questions that slow you down, then come back to them until the reasoning
feels automatic. Learners who revise this way walk into the exam room recognising the pattern
behind the questions instead of meeting them for the first time. Keep going - steady, honest
practice is what turns a difficult paper into a comfortable pass.
Q1 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
Which of the following best describes the primary advantage of the Cipher Block
Chaining (CBC) mode over Electronic Codebook (ECB) mode when encrypting a
large file with identical blocks?
A. CBC provides authentication in addition to confidentiality, whereas ECB does not.
B. CBC ensures that identical plaintext blocks produce different ciphertext blocks, thwarting
pattern analysis. CORRECT
C. CBC allows parallel encryption of blocks, improving performance over ECB.
D. CBC uses a counter that prevents replay attacks, which ECB cannot.
RATIONALE: CBC XORs each plaintext block with the previous ciphertext block before
encryption, so identical plaintext blocks yield different ciphertexts, hiding patterns. ECB encrypts
each block independently, preserving patterns. CBC does not provide authentication (A), parallel
encryption (C), or replay protection (D).
Page 2
,Q2 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
A security engineer must choose a hash function for a digital signature scheme
that requires resistance to both collision and preimage attacks. Which of the
following hash functions is currently considered most secure for this purpose?
A. MD5
B. SHA-1
C. SHA-256 CORRECT
D. RIPEMD-160
RATIONALE: SHA-256 is part of the SHA-2 family and remains resistant to known practical
collision and preimage attacks. MD5 and SHA-1 are broken for collision resistance, and
RIPEMD-160, while not broken, is less widely standardized and has a smaller output size,
making SHA-256 the most secure choice among the options.
Q3 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
In the context of the Diffie-Hellman key exchange, which of the following is the
primary purpose of using a large prime modulus and a generator?
A. To ensure that the shared secret is resistant to brute-force attacks by increasing the key
space. CORRECT
B. To prevent man-in-the-middle attacks by authenticating the parties.
C. To allow the use of smaller key sizes for symmetric encryption.
D. To enable the use of elliptic curve cryptography for efficiency.
RATIONALE: A large prime modulus and a generator increase the difficulty of solving the discrete
logarithm problem, thereby enlarging the effective key space and resisting brute-force attacks.
Diffie-Hellman alone does not authenticate parties (B). It does not directly allow smaller
symmetric keys (C) or enable ECC (D).
Page 3
, Q4 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
Which of the following statements accurately distinguishes a digital signature
from a message authentication code (MAC)?
A. A digital signature uses a symmetric key, while a MAC uses a public-private key pair.
B. A digital signature provides non-repudiation, whereas a MAC does not. CORRECT
C. A MAC provides confidentiality, while a digital signature provides only integrity.
D. A digital signature is faster to compute than a MAC for large messages.
RATIONALE: Digital signatures use asymmetric cryptography and provide non-repudiation
because the private key is unique to the signer. MACs use symmetric keys and do not provide
non-repudiation. The other options misstate key usage, security services, or performance
characteristics.
Q5 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
During a TLS handshake, the client and server negotiate a cipher suite. Which
component of the cipher suite specifies the algorithm used for key exchange?
A. The bulk encryption algorithm
B. The message authentication code algorithm
C. The key exchange algorithm CORRECT
D. The pseudorandom function
RATIONALE: The cipher suite includes a key exchange algorithm (e.g., ECDHE, RSA) that
determines how the premaster secret is established. The bulk encryption algorithm specifies
symmetric encryption, the MAC algorithm provides integrity, and the PRF derives keys, but none
of these define the key exchange method.
Page 4
(OBJECTIVE ASSESSMENT) QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES NEW 2026-2027 UPDATE
100 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Analyze and differentiate symmetric and asymmetric cryptographic algorithms based on security
properties and performance characteristics
2 Evaluate cryptographic hash functions and message authentication codes for integrity, collision
resistance, and preimage resistance
3 Apply key management principles, including key exchange, distribution, and storage, to design secure
systems
4 Interpret and critique digital signatures, certificates, and PKI trust models within contemporary security
frameworks
5 Identify and mitigate common cryptographic implementation vulnerabilities and protocol flaws
6 WGU D830 Introduction to Cryptography OA
7 Objective Assessment
8 Questions and Correct Answers with Rationales New 2026
9 2027 Update
10 Foundations of Cryptography and Information Security
11 Applied Cryptography and Information Security
12 Advanced Cryptography and Information Security
13 Cryptography and Information Security Review
ABSTRACT
Page 1
,This study document brings together 100 carefully worded exam questions drawn from WGU D830
Introduction to Cryptography OA (Objective Assessment) Questions and Correct Answers with
Rationales New 2026-2027 Update, with the strongest emphasis placed on Analyze and
differentiate symmetric and asymmetric cryptographic algorithms based on security properties and
performance characteristics, Evaluate cryptographic hash functions and message authentication
codes for integrity, collision resistance, and preimage resistance, Apply key management
principles, including key exchange, distribution, and storage and to design secure systems. Every
item follows the wording style and level of reasoning you meet in the real paper, and each one is
paired with a clear rationale so the correct choice is never a guess. Work through the set at your
own pace, mark the questions that slow you down, then come back to them until the reasoning
feels automatic. Learners who revise this way walk into the exam room recognising the pattern
behind the questions instead of meeting them for the first time. Keep going - steady, honest
practice is what turns a difficult paper into a comfortable pass.
Q1 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
Which of the following best describes the primary advantage of the Cipher Block
Chaining (CBC) mode over Electronic Codebook (ECB) mode when encrypting a
large file with identical blocks?
A. CBC provides authentication in addition to confidentiality, whereas ECB does not.
B. CBC ensures that identical plaintext blocks produce different ciphertext blocks, thwarting
pattern analysis. CORRECT
C. CBC allows parallel encryption of blocks, improving performance over ECB.
D. CBC uses a counter that prevents replay attacks, which ECB cannot.
RATIONALE: CBC XORs each plaintext block with the previous ciphertext block before
encryption, so identical plaintext blocks yield different ciphertexts, hiding patterns. ECB encrypts
each block independently, preserving patterns. CBC does not provide authentication (A), parallel
encryption (C), or replay protection (D).
Page 2
,Q2 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
A security engineer must choose a hash function for a digital signature scheme
that requires resistance to both collision and preimage attacks. Which of the
following hash functions is currently considered most secure for this purpose?
A. MD5
B. SHA-1
C. SHA-256 CORRECT
D. RIPEMD-160
RATIONALE: SHA-256 is part of the SHA-2 family and remains resistant to known practical
collision and preimage attacks. MD5 and SHA-1 are broken for collision resistance, and
RIPEMD-160, while not broken, is less widely standardized and has a smaller output size,
making SHA-256 the most secure choice among the options.
Q3 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
In the context of the Diffie-Hellman key exchange, which of the following is the
primary purpose of using a large prime modulus and a generator?
A. To ensure that the shared secret is resistant to brute-force attacks by increasing the key
space. CORRECT
B. To prevent man-in-the-middle attacks by authenticating the parties.
C. To allow the use of smaller key sizes for symmetric encryption.
D. To enable the use of elliptic curve cryptography for efficiency.
RATIONALE: A large prime modulus and a generator increase the difficulty of solving the discrete
logarithm problem, thereby enlarging the effective key space and resisting brute-force attacks.
Diffie-Hellman alone does not authenticate parties (B). It does not directly allow smaller
symmetric keys (C) or enable ECC (D).
Page 3
, Q4 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
Which of the following statements accurately distinguishes a digital signature
from a message authentication code (MAC)?
A. A digital signature uses a symmetric key, while a MAC uses a public-private key pair.
B. A digital signature provides non-repudiation, whereas a MAC does not. CORRECT
C. A MAC provides confidentiality, while a digital signature provides only integrity.
D. A digital signature is faster to compute than a MAC for large messages.
RATIONALE: Digital signatures use asymmetric cryptography and provide non-repudiation
because the private key is unique to the signer. MACs use symmetric keys and do not provide
non-repudiation. The other options misstate key usage, security services, or performance
characteristics.
Q5 ANALYZE AND DIFFERENTIATE SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHIC
ALGORITHMS BASED ON SECURITY PROPERTIES AND PERFORMANCE CHARACTERISTICS
During a TLS handshake, the client and server negotiate a cipher suite. Which
component of the cipher suite specifies the algorithm used for key exchange?
A. The bulk encryption algorithm
B. The message authentication code algorithm
C. The key exchange algorithm CORRECT
D. The pseudorandom function
RATIONALE: The cipher suite includes a key exchange algorithm (e.g., ECDHE, RSA) that
determines how the premaster secret is established. The bulk encryption algorithm specifies
symmetric encryption, the MAC algorithm provides integrity, and the PRF derives keys, but none
of these define the key exchange method.
Page 4
