,WGU D830 Introduction to Cryptography |PA| Exam Prep 2026 | 130+ Practice Questions
& Answers | Study Guide
Question 1
What role does modular arithmetic play in cryptographic algorithms?
A. Compressing files for transmission
B. Performing calculations within a finite set of numbers
C. Generating random passwords
D. Creating digital certificates
Correct Answer: B. Performing calculations within a finite set of numbers
Rationale: Modular arithmetic is fundamental to many cryptographic systems, including RSA
and Diffie-Hellman. It allows calculations to be performed within a fixed range of values,
creating mathematical complexity that strengthens encryption.
Question 2
How is lattice-based cryptography applied in modern encryption techniques?
A. By storing keys in cloud databases
B. Using geometric structures for cryptographic algorithms
C. Replacing encryption with hashing
D. Eliminating the need for key management
Correct Answer: B. Using geometric structures for cryptographic algorithms
Rationale: Lattice-based cryptography relies on complex mathematical problems involving
geometric lattices and is considered a promising approach for post-quantum cryptography.
Question 3
What is encryption?
A. Deleting sensitive data
B. Encoding messages
C. Compressing information
D. Verifying user identity
Correct Answer: B. Encoding messages
,Rationale: Encryption converts readable plaintext into unreadable ciphertext, ensuring that only
authorized parties can access the information.
Question 4
What role do large prime numbers play in cryptographic algorithms?
A. Reduce network traffic
B. Ensure security and strength
C. Increase storage capacity
D. Speed up data transmission
Correct Answer: B. Ensure security and strength
Rationale: Large prime numbers are essential to public-key cryptography systems such as RSA
because they make factoring calculations computationally difficult.
Question 5
A security architect is designing a system that uses encryption, key management, and
authentication services together. What is this combination known as?
A. Ciphertext
B. Hash Function
C. Cryptosystem
D. Blockchain
Correct Answer: C. Cryptosystem
Rationale: A cryptosystem consists of algorithms, keys, protocols, and procedures used to
provide secure communication.
Question 6
How are digital signatures used?
A. Encrypt data permanently
B. Verify authenticity and integrity
C. Replace certificates
D. Compress messages
, Correct Answer: B. Verify authenticity and integrity
Rationale: Digital signatures confirm that a message originated from the claimed sender and has
not been altered during transmission.
Question 7
A sender cannot deny having sent a digitally signed message. Which security principle is being
demonstrated?
A. Confidentiality
B. Availability
C. Nonrepudiation
D. Authorization
Correct Answer: C. Nonrepudiation
Rationale: Nonrepudiation prevents an individual from denying a previous action, such as
sending a digitally signed document.
Question 8
Which encryption method is considered symmetric encryption?
A. RSA
B. ECC
C. AES
D. Diffie-Hellman
Correct Answer: C. AES
Rationale: AES uses the same secret key for both encryption and decryption, making it a
symmetric encryption algorithm.
Question 9
Which of the following is an example of asymmetric encryption?
A. AES
B. DES
& Answers | Study Guide
Question 1
What role does modular arithmetic play in cryptographic algorithms?
A. Compressing files for transmission
B. Performing calculations within a finite set of numbers
C. Generating random passwords
D. Creating digital certificates
Correct Answer: B. Performing calculations within a finite set of numbers
Rationale: Modular arithmetic is fundamental to many cryptographic systems, including RSA
and Diffie-Hellman. It allows calculations to be performed within a fixed range of values,
creating mathematical complexity that strengthens encryption.
Question 2
How is lattice-based cryptography applied in modern encryption techniques?
A. By storing keys in cloud databases
B. Using geometric structures for cryptographic algorithms
C. Replacing encryption with hashing
D. Eliminating the need for key management
Correct Answer: B. Using geometric structures for cryptographic algorithms
Rationale: Lattice-based cryptography relies on complex mathematical problems involving
geometric lattices and is considered a promising approach for post-quantum cryptography.
Question 3
What is encryption?
A. Deleting sensitive data
B. Encoding messages
C. Compressing information
D. Verifying user identity
Correct Answer: B. Encoding messages
,Rationale: Encryption converts readable plaintext into unreadable ciphertext, ensuring that only
authorized parties can access the information.
Question 4
What role do large prime numbers play in cryptographic algorithms?
A. Reduce network traffic
B. Ensure security and strength
C. Increase storage capacity
D. Speed up data transmission
Correct Answer: B. Ensure security and strength
Rationale: Large prime numbers are essential to public-key cryptography systems such as RSA
because they make factoring calculations computationally difficult.
Question 5
A security architect is designing a system that uses encryption, key management, and
authentication services together. What is this combination known as?
A. Ciphertext
B. Hash Function
C. Cryptosystem
D. Blockchain
Correct Answer: C. Cryptosystem
Rationale: A cryptosystem consists of algorithms, keys, protocols, and procedures used to
provide secure communication.
Question 6
How are digital signatures used?
A. Encrypt data permanently
B. Verify authenticity and integrity
C. Replace certificates
D. Compress messages
, Correct Answer: B. Verify authenticity and integrity
Rationale: Digital signatures confirm that a message originated from the claimed sender and has
not been altered during transmission.
Question 7
A sender cannot deny having sent a digitally signed message. Which security principle is being
demonstrated?
A. Confidentiality
B. Availability
C. Nonrepudiation
D. Authorization
Correct Answer: C. Nonrepudiation
Rationale: Nonrepudiation prevents an individual from denying a previous action, such as
sending a digitally signed document.
Question 8
Which encryption method is considered symmetric encryption?
A. RSA
B. ECC
C. AES
D. Diffie-Hellman
Correct Answer: C. AES
Rationale: AES uses the same secret key for both encryption and decryption, making it a
symmetric encryption algorithm.
Question 9
Which of the following is an example of asymmetric encryption?
A. AES
B. DES
