WGU D334 CRYPTOGRAPHY – FULL STUDY
GUIDE & CONCEPT BREAKDOWN (2025
EDITION)
WGU D334 Cryptography: Practice Exam
1. The primary goal of cryptography is to ensure:
A. High-speed data transmission
B. Data integrity and confidentiality ✓
C. Data compression
D. Network bandwidth optimization
2. Which cryptographic concept ensures that a message sender cannot later deny sending a
message?
A. Confidentiality
B. Integrity
C. Authentication
D. Non-repudiation ✓
3. A substitution cipher that uses multiple alphabets is known as a:
A. Stream cipher
B. Polyalphabetic cipher ✓
C. Transposition cipher
D. Monoalphabetic cipher
4. The Caesar Cipher is a classic example of which type of cipher?
A. Transposition
B. Polyalphabetic substitution
C. Monoalphabetic substitution ✓
D. Asymmetric key
5. The Enigma machine implemented a complex form of which classical cipher?
A. Steganography
B. Scytale
C. Polyalphabetic substitution ✓
D. Hash function
,6. The process of converting plaintext into ciphertext is called:
A. Decryption
B. Cryptanalysis
C. Encryption ✓
D. Hashing
7. Which of the following is a fundamental principle of Kerckhoffs's principle?
A. A cipher should be secure even if everything about the system, except the key, is public
knowledge. ✓
B. A cipher should use a key length of at least 256 bits.
C. The encryption algorithm must be kept secret for security.
D. A cipher should only use asymmetric cryptography.
8. A cryptographic hash function must be:
A. Reversible
B. Predictable
C. Collision-resistant ✓
D. Based on a symmetric key
9. Which property is NOT a requirement for a secure cryptographic hash function?
A. Pre-image resistance
B. Fast reversibility ✓
C. Avalanche effect
D. Collision resistance
10. MD5 and SHA-1 are considered insecure for modern applications primarily because:
A. They are too slow.
B. They produce outputs that are too short.
C. Effective collision attacks have been found against them. ✓
D. They are symmetric algorithms.
11. What is the output length of a standard SHA-256 hash?
A. 128 bits
B. 160 bits
C. 256 bits ✓
D. 512 bits
12. A Message Authentication Code (MAC) is used to provide:
A. Only confidentiality
B. Only non-repudiation
,C. Confidentiality and integrity
D. Integrity and authentication ✓
13. HMAC (Hash-based MAC) combines a cryptographic hash function with what?
A. A public key
B. A secret key ✓
C. A digital certificate
D. A nonce
14. Which type of cryptography uses a single, shared key for both encryption and decryption?
A. Asymmetric Cryptography
B. Public Key Cryptography
C. Symmetric Cryptography ✓
D. Hash Functions
15. The major challenge with symmetric key cryptography is:
A. Its slow speed compared to asymmetric cryptography.
B. Its vulnerability to brute-force attacks.
C. The key distribution problem. ✓
D. Its inability to provide authentication.
16. Which of the following is a symmetric block cipher?
A. RSA
B. Diffie-Hellman
C. AES ✓
D. ECC
17. DES (Data Encryption Standard) uses a key size of:
A. 56 bits ✓
B. 128 bits
C. 192 bits
D. 256 bits
18. AES (Advanced Encryption Standard) can use all of the following key sizes EXCEPT:
A. 128 bits
B. 192 bits
C. 256 bits
D. 512 bits ✓
19. A mode of operation that turns a block cipher into a stream cipher is:
A. ECB (Electronic Codebook)
, B. CBC (Cipher Block Chaining)
C. CFB (Cipher Feedback) ✓
D. AES
20. Which block cipher mode uses an Initialization Vector (IV) and chains blocks together to
hide patterns?
A. ECB
B. CBC ✓
C. RSA
D. PKI
21. The main weakness of the ECB (Electronic Codebook) mode is that:
A. It is the slowest mode.
B. Identical plaintext blocks produce identical ciphertext blocks. ✓
C. It requires asymmetric keys.
D. It does not provide integrity.
22. Which of the following is an asymmetric (public key) cryptography algorithm?
A. AES
B. 3DES
C. Blowfish
D. RSA ✓
23. The security of the RSA algorithm is based on the computational difficulty of:
A. Finding discrete logarithms in a finite field.
B. Factoring large prime numbers. ✓
C. Solving elliptic curve discrete logarithms.
D. Reversing a one-way hash function.
24. In RSA, the public key consists of:
A. n and d
B. n and e ✓
C. p and q
D. d only
25. Diffie-Hellman key exchange allows two parties to:
A. Digitally sign a document.
B. Establish a shared secret key over an insecure channel. ✓
C. Encrypt large amounts of data efficiently.
D. Verify the integrity of a message.
GUIDE & CONCEPT BREAKDOWN (2025
EDITION)
WGU D334 Cryptography: Practice Exam
1. The primary goal of cryptography is to ensure:
A. High-speed data transmission
B. Data integrity and confidentiality ✓
C. Data compression
D. Network bandwidth optimization
2. Which cryptographic concept ensures that a message sender cannot later deny sending a
message?
A. Confidentiality
B. Integrity
C. Authentication
D. Non-repudiation ✓
3. A substitution cipher that uses multiple alphabets is known as a:
A. Stream cipher
B. Polyalphabetic cipher ✓
C. Transposition cipher
D. Monoalphabetic cipher
4. The Caesar Cipher is a classic example of which type of cipher?
A. Transposition
B. Polyalphabetic substitution
C. Monoalphabetic substitution ✓
D. Asymmetric key
5. The Enigma machine implemented a complex form of which classical cipher?
A. Steganography
B. Scytale
C. Polyalphabetic substitution ✓
D. Hash function
,6. The process of converting plaintext into ciphertext is called:
A. Decryption
B. Cryptanalysis
C. Encryption ✓
D. Hashing
7. Which of the following is a fundamental principle of Kerckhoffs's principle?
A. A cipher should be secure even if everything about the system, except the key, is public
knowledge. ✓
B. A cipher should use a key length of at least 256 bits.
C. The encryption algorithm must be kept secret for security.
D. A cipher should only use asymmetric cryptography.
8. A cryptographic hash function must be:
A. Reversible
B. Predictable
C. Collision-resistant ✓
D. Based on a symmetric key
9. Which property is NOT a requirement for a secure cryptographic hash function?
A. Pre-image resistance
B. Fast reversibility ✓
C. Avalanche effect
D. Collision resistance
10. MD5 and SHA-1 are considered insecure for modern applications primarily because:
A. They are too slow.
B. They produce outputs that are too short.
C. Effective collision attacks have been found against them. ✓
D. They are symmetric algorithms.
11. What is the output length of a standard SHA-256 hash?
A. 128 bits
B. 160 bits
C. 256 bits ✓
D. 512 bits
12. A Message Authentication Code (MAC) is used to provide:
A. Only confidentiality
B. Only non-repudiation
,C. Confidentiality and integrity
D. Integrity and authentication ✓
13. HMAC (Hash-based MAC) combines a cryptographic hash function with what?
A. A public key
B. A secret key ✓
C. A digital certificate
D. A nonce
14. Which type of cryptography uses a single, shared key for both encryption and decryption?
A. Asymmetric Cryptography
B. Public Key Cryptography
C. Symmetric Cryptography ✓
D. Hash Functions
15. The major challenge with symmetric key cryptography is:
A. Its slow speed compared to asymmetric cryptography.
B. Its vulnerability to brute-force attacks.
C. The key distribution problem. ✓
D. Its inability to provide authentication.
16. Which of the following is a symmetric block cipher?
A. RSA
B. Diffie-Hellman
C. AES ✓
D. ECC
17. DES (Data Encryption Standard) uses a key size of:
A. 56 bits ✓
B. 128 bits
C. 192 bits
D. 256 bits
18. AES (Advanced Encryption Standard) can use all of the following key sizes EXCEPT:
A. 128 bits
B. 192 bits
C. 256 bits
D. 512 bits ✓
19. A mode of operation that turns a block cipher into a stream cipher is:
A. ECB (Electronic Codebook)
, B. CBC (Cipher Block Chaining)
C. CFB (Cipher Feedback) ✓
D. AES
20. Which block cipher mode uses an Initialization Vector (IV) and chains blocks together to
hide patterns?
A. ECB
B. CBC ✓
C. RSA
D. PKI
21. The main weakness of the ECB (Electronic Codebook) mode is that:
A. It is the slowest mode.
B. Identical plaintext blocks produce identical ciphertext blocks. ✓
C. It requires asymmetric keys.
D. It does not provide integrity.
22. Which of the following is an asymmetric (public key) cryptography algorithm?
A. AES
B. 3DES
C. Blowfish
D. RSA ✓
23. The security of the RSA algorithm is based on the computational difficulty of:
A. Finding discrete logarithms in a finite field.
B. Factoring large prime numbers. ✓
C. Solving elliptic curve discrete logarithms.
D. Reversing a one-way hash function.
24. In RSA, the public key consists of:
A. n and d
B. n and e ✓
C. p and q
D. d only
25. Diffie-Hellman key exchange allows two parties to:
A. Digitally sign a document.
B. Establish a shared secret key over an insecure channel. ✓
C. Encrypt large amounts of data efficiently.
D. Verify the integrity of a message.
