WISEMAN STUDY SERIES | WGU D315
WISEMAN STUDY SERIES
WGU D334
Introduction to Cryptography
Comprehensive Study Guide
Algorithms • Hashing • PKI • Key Management • Cryptanalysis
Edition Scope Use
2026 WGU-aligned cryptography foundations Learn, compare, apply, review
Original educational reference — not affiliated with or endorsed by WGU
Page 1
,WISEMAN STUDY SERIES | WGU D315
How to Use This Guide
D334 rewards precise distinctions: purpose, key type, key/block/output size, workflow, weakness, and appropriate
modern use. Build a comparison map before memorizing isolated facts.
Three-pass method
Use active recall rather than repeated reading.
• Pass 1: understand confidentiality, integrity, authentication, and non-repudiation.
• Pass 2: compare algorithms, modes, hashes, PKI objects, and attacks.
• Pass 3: solve workflows and explain why alternatives fail.
Published course alignment
The public WGU description emphasizes organizational guidance, cryptanalysis requirements, and
symmetric/asymmetric implementation.
• Always connect an algorithm choice to data, threat, performance, interoperability, and policy requirements.
Knowledge check
1. What five facts should you recall for an algorithm?
Answer: Type, purpose, key size, block/output size, and present security status.
Page 2
, WISEMAN STUDY SERIES | WGU D315
1. Cryptographic Foundations
Cryptography applies mathematical transformations to protect information against adversarial behavior.
Vocabulary
Plaintext enters an algorithm with a key and produces ciphertext; decryption reverses the transformation with the required
key.
• Cryptography designs and applies protection.
• Cryptanalysis studies how to defeat or evaluate it.
• Cryptology includes both disciplines.
Security services
A mechanism must be matched to the objective.
• Encryption supports confidentiality.
• Hashes and signatures support integrity.
• Authentication establishes identity or origin.
• Digital signatures can support non-repudiation.
Concept Meaning Example
Confusion Each ciphertext bit depends on complex Substitution structures
key relationships
Diffusion One plaintext change spreads across many Permutation/mixing
ciphertext bits
Kerckhoffs’s principle Security should depend on the key, not Publicly reviewed algorithms
algorithm secrecy
Entropy Uncertainty in keys or random values CSPRNG output
Knowledge check
1. Why is encoding not encryption?
Answer: Encoding changes representation and has no secret key or confidentiality goal.
2. What protects a secret algorithm after it becomes public?
Answer: Nothing reliable; modern design assumes the algorithm is known and the key remains secret.
Page 3
WISEMAN STUDY SERIES
WGU D334
Introduction to Cryptography
Comprehensive Study Guide
Algorithms • Hashing • PKI • Key Management • Cryptanalysis
Edition Scope Use
2026 WGU-aligned cryptography foundations Learn, compare, apply, review
Original educational reference — not affiliated with or endorsed by WGU
Page 1
,WISEMAN STUDY SERIES | WGU D315
How to Use This Guide
D334 rewards precise distinctions: purpose, key type, key/block/output size, workflow, weakness, and appropriate
modern use. Build a comparison map before memorizing isolated facts.
Three-pass method
Use active recall rather than repeated reading.
• Pass 1: understand confidentiality, integrity, authentication, and non-repudiation.
• Pass 2: compare algorithms, modes, hashes, PKI objects, and attacks.
• Pass 3: solve workflows and explain why alternatives fail.
Published course alignment
The public WGU description emphasizes organizational guidance, cryptanalysis requirements, and
symmetric/asymmetric implementation.
• Always connect an algorithm choice to data, threat, performance, interoperability, and policy requirements.
Knowledge check
1. What five facts should you recall for an algorithm?
Answer: Type, purpose, key size, block/output size, and present security status.
Page 2
, WISEMAN STUDY SERIES | WGU D315
1. Cryptographic Foundations
Cryptography applies mathematical transformations to protect information against adversarial behavior.
Vocabulary
Plaintext enters an algorithm with a key and produces ciphertext; decryption reverses the transformation with the required
key.
• Cryptography designs and applies protection.
• Cryptanalysis studies how to defeat or evaluate it.
• Cryptology includes both disciplines.
Security services
A mechanism must be matched to the objective.
• Encryption supports confidentiality.
• Hashes and signatures support integrity.
• Authentication establishes identity or origin.
• Digital signatures can support non-repudiation.
Concept Meaning Example
Confusion Each ciphertext bit depends on complex Substitution structures
key relationships
Diffusion One plaintext change spreads across many Permutation/mixing
ciphertext bits
Kerckhoffs’s principle Security should depend on the key, not Publicly reviewed algorithms
algorithm secrecy
Entropy Uncertainty in keys or random values CSPRNG output
Knowledge check
1. Why is encoding not encryption?
Answer: Encoding changes representation and has no secret key or confidentiality goal.
2. What protects a secret algorithm after it becomes public?
Answer: Nothing reliable; modern design assumes the algorithm is known and the key remains secret.
Page 3
