WGU D830 YCN1 Task 1 Practice Questions
and Answers 2026–2027 | 250 MCQs with
Detailed Rationales | AES, RSA, OpenSSL &
SCP Study Guide
Section 1: Cryptography fundamentals (Questions 1–25)
1. What is the primary purpose of encryption?
A. Compress files to reduce storage requirements B. Convert readable information into a
protected form C. Remove duplicate information from a database D. Increase the speed of
network communication
Correct answer: B
Explanation: Encryption transforms plaintext into ciphertext using a cryptographic algorithm
and key, helping protect confidentiality from unauthorized readers.
2. What is plaintext?
A. Information in its original readable or usable form before encryption B. Information that
has been permanently deleted C. An encrypted private key D. A cryptographic hash value
Correct answer: A
Explanation: Plaintext is the input data that encryption protects. Depending on the
application, it may be text, a document, an image, or another type of digital information.
,3. What is ciphertext?
A. A password stored in a password manager B. A public certificate C. A file that has never
been encrypted D. The transformed output produced by encryption
Correct answer: D
Explanation: Ciphertext is the output of an encryption operation. It is intended to be
unintelligible without the appropriate decryption key or other required information.
4. Which cryptographic approach uses the same secret key for encryption and
decryption?
A. Digital signatures B. Asymmetric encryption C. Symmetric encryption D. Public-key
certification
Correct answer: C
Explanation: Symmetric encryption uses a shared secret key for both encryption and
decryption, making secure key distribution an important requirement.
5. Which cryptographic approach uses a mathematically related public and private
key pair?
A. Symmetric encryption B. Asymmetric cryptography C. Data compression D. Simple
substitution without a key pair
Correct answer: B
Explanation: Asymmetric cryptography uses a public key and a corresponding private key.
The keys have related mathematical properties but serve different roles.
,6. What is the primary security purpose of a cryptographic hash function?
A. Provide a fixed-length digest useful for integrity verification B. Encrypt data so that only a
private key can decrypt it C. Transfer files between computers D. Guarantee that a sender
is authorized
Correct answer: A
Explanation: A cryptographic hash produces a digest from input data. Comparing securely
obtained digests can reveal changes, although a hash alone does not authenticate its
source.
7. Which security objective means that information is accessible to authorized users
when needed?
A. Confidentiality B. Nonrepudiation C. Integrity D. Availability
Correct answer: D
Explanation: Availability concerns reliable access to information and services. Encryption
alone does not guarantee availability.
8. Which security objective protects information against unauthorized modification?
A. Availability B. Compression C. Integrity D. Redundancy
Correct answer: C
Explanation: Integrity ensures that information remains accurate and complete.
Cryptographic hashes, message authentication codes, and digital signatures can help
detect unauthorized changes.
, 9. What is the main purpose of a cryptographic key?
A. Determine the file's extension B. Control a cryptographic operation, such as encryption,
decryption, or signing C. Automatically remove malware D. Increase the file's storage
capacity
Correct answer: B
Explanation: Cryptographic keys provide the secret or public/private values required by
cryptographic algorithms to perform specific security operations.
10. What does key length generally describe?
A. The number of characters in a filename B. The size of the encrypted document C. The
time required to transfer a file D. The number of bits used to represent a cryptographic key
Correct answer: D
Explanation: Key length is measured in bits and is one factor affecting security. The actual
strength also depends on the algorithm, key generation, implementation, and threat model.
11. Which algorithm is commonly used for modern symmetric encryption?
A. AES B. RSA C. SHA-256 D. X.509
Correct answer: A
Explanation: Advanced Encryption Standard (AES) is a widely used symmetric block cipher.
RSA is an asymmetric algorithm, SHA-256 is a hash function, and X.509 defines certificate
formats.
12. Which algorithm is commonly associated with public-key cryptography?
and Answers 2026–2027 | 250 MCQs with
Detailed Rationales | AES, RSA, OpenSSL &
SCP Study Guide
Section 1: Cryptography fundamentals (Questions 1–25)
1. What is the primary purpose of encryption?
A. Compress files to reduce storage requirements B. Convert readable information into a
protected form C. Remove duplicate information from a database D. Increase the speed of
network communication
Correct answer: B
Explanation: Encryption transforms plaintext into ciphertext using a cryptographic algorithm
and key, helping protect confidentiality from unauthorized readers.
2. What is plaintext?
A. Information in its original readable or usable form before encryption B. Information that
has been permanently deleted C. An encrypted private key D. A cryptographic hash value
Correct answer: A
Explanation: Plaintext is the input data that encryption protects. Depending on the
application, it may be text, a document, an image, or another type of digital information.
,3. What is ciphertext?
A. A password stored in a password manager B. A public certificate C. A file that has never
been encrypted D. The transformed output produced by encryption
Correct answer: D
Explanation: Ciphertext is the output of an encryption operation. It is intended to be
unintelligible without the appropriate decryption key or other required information.
4. Which cryptographic approach uses the same secret key for encryption and
decryption?
A. Digital signatures B. Asymmetric encryption C. Symmetric encryption D. Public-key
certification
Correct answer: C
Explanation: Symmetric encryption uses a shared secret key for both encryption and
decryption, making secure key distribution an important requirement.
5. Which cryptographic approach uses a mathematically related public and private
key pair?
A. Symmetric encryption B. Asymmetric cryptography C. Data compression D. Simple
substitution without a key pair
Correct answer: B
Explanation: Asymmetric cryptography uses a public key and a corresponding private key.
The keys have related mathematical properties but serve different roles.
,6. What is the primary security purpose of a cryptographic hash function?
A. Provide a fixed-length digest useful for integrity verification B. Encrypt data so that only a
private key can decrypt it C. Transfer files between computers D. Guarantee that a sender
is authorized
Correct answer: A
Explanation: A cryptographic hash produces a digest from input data. Comparing securely
obtained digests can reveal changes, although a hash alone does not authenticate its
source.
7. Which security objective means that information is accessible to authorized users
when needed?
A. Confidentiality B. Nonrepudiation C. Integrity D. Availability
Correct answer: D
Explanation: Availability concerns reliable access to information and services. Encryption
alone does not guarantee availability.
8. Which security objective protects information against unauthorized modification?
A. Availability B. Compression C. Integrity D. Redundancy
Correct answer: C
Explanation: Integrity ensures that information remains accurate and complete.
Cryptographic hashes, message authentication codes, and digital signatures can help
detect unauthorized changes.
, 9. What is the main purpose of a cryptographic key?
A. Determine the file's extension B. Control a cryptographic operation, such as encryption,
decryption, or signing C. Automatically remove malware D. Increase the file's storage
capacity
Correct answer: B
Explanation: Cryptographic keys provide the secret or public/private values required by
cryptographic algorithms to perform specific security operations.
10. What does key length generally describe?
A. The number of characters in a filename B. The size of the encrypted document C. The
time required to transfer a file D. The number of bits used to represent a cryptographic key
Correct answer: D
Explanation: Key length is measured in bits and is one factor affecting security. The actual
strength also depends on the algorithm, key generation, implementation, and threat model.
11. Which algorithm is commonly used for modern symmetric encryption?
A. AES B. RSA C. SHA-256 D. X.509
Correct answer: A
Explanation: Advanced Encryption Standard (AES) is a widely used symmetric block cipher.
RSA is an asymmetric algorithm, SHA-256 is a hash function, and X.509 defines certificate
formats.
12. Which algorithm is commonly associated with public-key cryptography?
