WGU C839 OBJECTIVE ASSESSMENT 2
LATEST VERSIONS (VERSION A & B)
2024-2025 /WGU C839 INTRODUCTION
TO CRYPTOGRAPHY OA ACTUAL
EXAM
Which encryption standard uses the same key to encrypt and decrypt messages? – answer
Symmetric
Which algorithm is designated as a Type 2 product by the National Security Agency (NSA)? –
answer Skipjack
What is the most commonly used format for certificates? – answer X.509 v3
What is referenced to determine if a certificate has been revoked? - answer Certificate
revocation list (CRL)
What needs to be installed on end users' computers to allow them to trust applications that have
been digitally signed by the developer? – answer Sender's public key
Which type of certificate must be certified by an authority to verify it with other participants? –
answer Public Certificate
What is an attribute of the Rivest Cipher 4 (RC4) algorithm? – answer It requires a unique
nonce.
Which mode generates the key stream with a nonce and incrementing value? – answer Counter
(CTR)
Which mode is a stream algorithm that concatenates an incrementing value with a nonce? –
answer Counter (CTR)
Which key would an administrator use to encrypt data so only the CEO can decrypt it? – answer
CEO's public key
What is the result of a hash function? – answer Digest
What is used to efficiently encrypt large files? – answer Symmetric encryption
An administrator needs to encrypt the following word with the Atbash cipher: security what is
the correct cipher text. – answer hvxfirgb
, Which cryptographic algorithm has a 128-bit hash size? - answer Message Digest Algorithm 5
(MD5)
Which characteristic makes a hashing function suitable for use in signature schemes? - answer
Collision resistance
Which attribute of a hashing function makes a birthday attack possible? - answer Partial-
message collision
Which hash algorithm produces a 160-bit output value? – answer SHA-1
What does cipher block chaining (CBC) use with the key to encrypt subsequent blocks of
plaintext? - answer Previous generated cipher text
Which mode produces the same cipher text from two identical plaintext blocks? - answer
Electronic codebook (ECB)
Which encryption mode is least secure? - answer Electronic codebook (ECB)
What is the mathematical formula used for symmetric decryption? – answer P = E (K,C)
Which algorithm relies on factoring the product of large prime numbers? – answer Rivest-
Shamir-Adleman
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? – answer Pretty Good Privacy (PGP)
Which concept stipulates that algorithms should be openly shared and scrutinized, but keys must
be absolutely secured? – answer Kerckhoffs's principle
Which encryption process minimizes known plaintext attacks against Advanced Encryption
Standard (AES)? – answer randomizing the initialization vector
What prevents a rainbow table attack during the encryption process? – answer Salting
Which factor increases the required number of attempts in a brute-force attack? – answer Larger
key size
What is a vulnerability of the Data Encryption Standard (DES)? – answer Key length is too
short.
Which block size does the Advanced Encryption Standard (AES) use? – answer 128
LATEST VERSIONS (VERSION A & B)
2024-2025 /WGU C839 INTRODUCTION
TO CRYPTOGRAPHY OA ACTUAL
EXAM
Which encryption standard uses the same key to encrypt and decrypt messages? – answer
Symmetric
Which algorithm is designated as a Type 2 product by the National Security Agency (NSA)? –
answer Skipjack
What is the most commonly used format for certificates? – answer X.509 v3
What is referenced to determine if a certificate has been revoked? - answer Certificate
revocation list (CRL)
What needs to be installed on end users' computers to allow them to trust applications that have
been digitally signed by the developer? – answer Sender's public key
Which type of certificate must be certified by an authority to verify it with other participants? –
answer Public Certificate
What is an attribute of the Rivest Cipher 4 (RC4) algorithm? – answer It requires a unique
nonce.
Which mode generates the key stream with a nonce and incrementing value? – answer Counter
(CTR)
Which mode is a stream algorithm that concatenates an incrementing value with a nonce? –
answer Counter (CTR)
Which key would an administrator use to encrypt data so only the CEO can decrypt it? – answer
CEO's public key
What is the result of a hash function? – answer Digest
What is used to efficiently encrypt large files? – answer Symmetric encryption
An administrator needs to encrypt the following word with the Atbash cipher: security what is
the correct cipher text. – answer hvxfirgb
, Which cryptographic algorithm has a 128-bit hash size? - answer Message Digest Algorithm 5
(MD5)
Which characteristic makes a hashing function suitable for use in signature schemes? - answer
Collision resistance
Which attribute of a hashing function makes a birthday attack possible? - answer Partial-
message collision
Which hash algorithm produces a 160-bit output value? – answer SHA-1
What does cipher block chaining (CBC) use with the key to encrypt subsequent blocks of
plaintext? - answer Previous generated cipher text
Which mode produces the same cipher text from two identical plaintext blocks? - answer
Electronic codebook (ECB)
Which encryption mode is least secure? - answer Electronic codebook (ECB)
What is the mathematical formula used for symmetric decryption? – answer P = E (K,C)
Which algorithm relies on factoring the product of large prime numbers? – answer Rivest-
Shamir-Adleman
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? – answer Pretty Good Privacy (PGP)
Which concept stipulates that algorithms should be openly shared and scrutinized, but keys must
be absolutely secured? – answer Kerckhoffs's principle
Which encryption process minimizes known plaintext attacks against Advanced Encryption
Standard (AES)? – answer randomizing the initialization vector
What prevents a rainbow table attack during the encryption process? – answer Salting
Which factor increases the required number of attempts in a brute-force attack? – answer Larger
key size
What is a vulnerability of the Data Encryption Standard (DES)? – answer Key length is too
short.
Which block size does the Advanced Encryption Standard (AES) use? – answer 128
