WGU C839 OA EXAM 100+ REAL EXAM QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)|
AGRADE
1. Which encryption standard uses the same key to encrypt and decrypt
messages?: Symmetric
2. Which algorithm is designated as a Type 2 product by the National
Security Agency (NSA)?: Skipjack
3. What is the most commonly used format for certificates?: X.509 v3
4. What is referenced to determine if a certificate has been revoked?:
Certificate revocation list (CRL)
5. What needs to be installed on end users' computers to allow them to
trust applications that have been digitally signed by the developer?:
Sender's public key
6. Which type of certificate must be certified by an authority to verify it
with other participants?: Public Certificate
7. What is an attribute of the Rivest Cipher 4 (RC4) algorithm?: It requires a
unique nonce.
8. Which mode generates the key stream with a nonce and incrementing
value?: Counter (CTR)
,9. Which mode is a stream algorithm that concatenates an incrementing
value with a nonce?: Counter (CTR)
10. Which key would an administrator use to encrypt data so only the CEO
can decrypt it?: CEO's public key
11. What is the result of a hash function?: Digest
12. What is used to efficiently encrypt large files?: Symmetric encryption
13. 13. An administrator needs to encrypt the following word with the
Atbash cipher: security What is the correct ciphertext?: hvxfirgb
14. Which cryptographic algorithm has a 128-bit hash size?: Message
Digest Algorithm 5 (MD5)
15. Which characteristic makes a hashing function suitable for use in
signature schemes?: Collision resistance
16. Which attribute of a hashing function makes a birthday attack
possible?: Partial-message collision
17. Which hash algorithm produces a 160-bit output value?: SHA-1
18. What does cipher block chaining (CBC) use with the key to encrypt
subsequent blocks of plaintext?: Previous generated ciphertext
19. Which mode produces the same ciphertext from two identical plaintext
blocks?: Electronic codebook (ECB)
, 20. Which encryption mode is least secure?: Electronic codebook (ECB)
21. What is the mathematical formula used for symmetric decryption?: P =
E (K,C)
22 Which algorithm relies on factoring the product of large prime
numbers?-
: Rivest-Shamir-Adleman
23. Which encryption technology is a serial combination of hashing, data
compression, symmetric-key cryptography, and public key infrastructure
(PKI) and can be used for encrypting texts, emails, files, and directories or
for full disk encryption?: Pretty Good Privacy (PGP)
24. Which concept stipulates that algorithms should be openly shared
and scrutinized, but keys must be absolutely secured?: Kerckhoffs's
principle
25. Which encryption process minimizes known plaintext attacks against
Advanced Encryption Standard (AES)?: Randomizing the initialization vector
26. What prevents a rainbow table attack during the encryption process?:
Salting
27. Which factor increases the required number of attempts in a brute-
force attack?: Larger key size
AND CORRECT ANSWERS (VERIFIED ANSWERS)|
AGRADE
1. Which encryption standard uses the same key to encrypt and decrypt
messages?: Symmetric
2. Which algorithm is designated as a Type 2 product by the National
Security Agency (NSA)?: Skipjack
3. What is the most commonly used format for certificates?: X.509 v3
4. What is referenced to determine if a certificate has been revoked?:
Certificate revocation list (CRL)
5. What needs to be installed on end users' computers to allow them to
trust applications that have been digitally signed by the developer?:
Sender's public key
6. Which type of certificate must be certified by an authority to verify it
with other participants?: Public Certificate
7. What is an attribute of the Rivest Cipher 4 (RC4) algorithm?: It requires a
unique nonce.
8. Which mode generates the key stream with a nonce and incrementing
value?: Counter (CTR)
,9. Which mode is a stream algorithm that concatenates an incrementing
value with a nonce?: Counter (CTR)
10. Which key would an administrator use to encrypt data so only the CEO
can decrypt it?: CEO's public key
11. What is the result of a hash function?: Digest
12. What is used to efficiently encrypt large files?: Symmetric encryption
13. 13. An administrator needs to encrypt the following word with the
Atbash cipher: security What is the correct ciphertext?: hvxfirgb
14. Which cryptographic algorithm has a 128-bit hash size?: Message
Digest Algorithm 5 (MD5)
15. Which characteristic makes a hashing function suitable for use in
signature schemes?: Collision resistance
16. Which attribute of a hashing function makes a birthday attack
possible?: Partial-message collision
17. Which hash algorithm produces a 160-bit output value?: SHA-1
18. What does cipher block chaining (CBC) use with the key to encrypt
subsequent blocks of plaintext?: Previous generated ciphertext
19. Which mode produces the same ciphertext from two identical plaintext
blocks?: Electronic codebook (ECB)
, 20. Which encryption mode is least secure?: Electronic codebook (ECB)
21. What is the mathematical formula used for symmetric decryption?: P =
E (K,C)
22 Which algorithm relies on factoring the product of large prime
numbers?-
: Rivest-Shamir-Adleman
23. Which encryption technology is a serial combination of hashing, data
compression, symmetric-key cryptography, and public key infrastructure
(PKI) and can be used for encrypting texts, emails, files, and directories or
for full disk encryption?: Pretty Good Privacy (PGP)
24. Which concept stipulates that algorithms should be openly shared
and scrutinized, but keys must be absolutely secured?: Kerckhoffs's
principle
25. Which encryption process minimizes known plaintext attacks against
Advanced Encryption Standard (AES)?: Randomizing the initialization vector
26. What prevents a rainbow table attack during the encryption process?:
Salting
27. Which factor increases the required number of attempts in a brute-
force attack?: Larger key size
