WGU C839 INTRO TO CRYPTOGRAPHY 2025
OA PREPARATION TEST BANK WITH 690
REAL EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS GRADED A+/ C839
PREP FOR OA AND PRE-ASSESSMENT
a cryptographic algorithm or protocol tailored for implementation in constrained
environments, including RFID tags, sensors, contactless smart cards, and
healthcare devices
lightweight cryptography
Which backdoor cryptography method involves having a copy of the encryption
key that law enforcement agents could use if they require access to the data?
A Key escrow
B Encryption by default
C RSA cracking
D NOBUS backdoor
A
Which of the following is NOT required for a hash?
A Minimum key length of 256 bits
B Variable-length input, fixed-length output
C Non-reversible
D Few collisions
A
A system administrator received an encrypted message from one of the company's
software vendors. Which cryptographic technique can the system administrator use
to authenticate the message sender and also ensure that the message has not been
tampered with?
pg. 1
,A One-time passwords (OTP)
B Salting
C LM hash
D Hash-based message authentication code (HMAC)
D
A developer wants to install a newly released patch received from a software
manufacturer. Which cryptographic algorithm can the developer use to trust that
the software truly came from the vendor and that the patch has not been altered or
manipulated?
A Public-key algorithm
B Secret-key algorithm
C Hashing function
D Digital signature algorithms
D
Which internationally recognized standard is used in public-key infrastructure
(PKI) to define the format of public-key certificates?
A FIPS 199
B Digital Signature Standard (DSS)
C FIPS 140-2
D X.509 standard
D
Which key method is used to create the tunnel in SSL/TLS connections?
A Session key method
B Symmetric key method
C Hashing method
D Asymmetric key method
B
Who sends the digital certificate and the selected cipher suites to use during RSA
key exchange in HTTPS connections?
pg. 2
,A Neither the server nor the client
B The client
C The server and the client
D The server
D
the process by which VPN packets reach their intended destination, which is
typically a private network
tunneling
a secure, encrypted connection over a publicly shared network
virtual private network (VPN)
using subscriber computers to route data packets over the internet, instead of using
publicly available routers.
onion routing
Which encryption cracking method involves an intruder sending a legitimate
message into the network at some future time?
A Time attack
B Cut-and-paste
C Chosen-ciphertext
D Replay system
D
when a copy of the encryption key is kept in escrow so that it can be used by a
government agent
key escrow
where it is mathematically possible for government agents to crack the encryption,
but no one else can
NOBUS ("nobody but us") backdoor
An intruder wants to break an encrypted message. After successfully accessing the
crypto device, the attacker first runs a plaintext through the device to see how its
encryption process works. Then the intruder alters the plaintext to see how the
pg. 3
, alteration affects the ciphertext that is being generated. What attack method is the
intruder using?
A Chosen attack
B Known plaintext attack
C Ciphertext-only attack
D Adaptive chosen attack
D
In the process of doing an encryption and decryption, a security engineer steps
away for lunch. While the security engineer was gone, an unsuspecting intruder sat
down at the engineer's desk and ran ciphertext through the crypto device to see the
result. Which attack method best describes this scenario?
A Adaptive chosen attack
B Chosen attack
C Adaptive chosen ciphertext attack
D Chosen ciphertext attack
D
the study of ciphertext, ciphers, and cryptosystems with the aim of understanding
how they work and finding and improving techniques for defeating or weakening
them
cryptanalysis
the process of systematically entering every word in a dictionary as a password to
see if the hashed code matches the one in the password file.
dictionary attack
Which combination of applications mostly uses lightweight cryptography?
A Tablets and RFID
B Servers and RFID
C Desktops and smartphones
D RFID and sensor networks
D
pg. 4
OA PREPARATION TEST BANK WITH 690
REAL EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS GRADED A+/ C839
PREP FOR OA AND PRE-ASSESSMENT
a cryptographic algorithm or protocol tailored for implementation in constrained
environments, including RFID tags, sensors, contactless smart cards, and
healthcare devices
lightweight cryptography
Which backdoor cryptography method involves having a copy of the encryption
key that law enforcement agents could use if they require access to the data?
A Key escrow
B Encryption by default
C RSA cracking
D NOBUS backdoor
A
Which of the following is NOT required for a hash?
A Minimum key length of 256 bits
B Variable-length input, fixed-length output
C Non-reversible
D Few collisions
A
A system administrator received an encrypted message from one of the company's
software vendors. Which cryptographic technique can the system administrator use
to authenticate the message sender and also ensure that the message has not been
tampered with?
pg. 1
,A One-time passwords (OTP)
B Salting
C LM hash
D Hash-based message authentication code (HMAC)
D
A developer wants to install a newly released patch received from a software
manufacturer. Which cryptographic algorithm can the developer use to trust that
the software truly came from the vendor and that the patch has not been altered or
manipulated?
A Public-key algorithm
B Secret-key algorithm
C Hashing function
D Digital signature algorithms
D
Which internationally recognized standard is used in public-key infrastructure
(PKI) to define the format of public-key certificates?
A FIPS 199
B Digital Signature Standard (DSS)
C FIPS 140-2
D X.509 standard
D
Which key method is used to create the tunnel in SSL/TLS connections?
A Session key method
B Symmetric key method
C Hashing method
D Asymmetric key method
B
Who sends the digital certificate and the selected cipher suites to use during RSA
key exchange in HTTPS connections?
pg. 2
,A Neither the server nor the client
B The client
C The server and the client
D The server
D
the process by which VPN packets reach their intended destination, which is
typically a private network
tunneling
a secure, encrypted connection over a publicly shared network
virtual private network (VPN)
using subscriber computers to route data packets over the internet, instead of using
publicly available routers.
onion routing
Which encryption cracking method involves an intruder sending a legitimate
message into the network at some future time?
A Time attack
B Cut-and-paste
C Chosen-ciphertext
D Replay system
D
when a copy of the encryption key is kept in escrow so that it can be used by a
government agent
key escrow
where it is mathematically possible for government agents to crack the encryption,
but no one else can
NOBUS ("nobody but us") backdoor
An intruder wants to break an encrypted message. After successfully accessing the
crypto device, the attacker first runs a plaintext through the device to see how its
encryption process works. Then the intruder alters the plaintext to see how the
pg. 3
, alteration affects the ciphertext that is being generated. What attack method is the
intruder using?
A Chosen attack
B Known plaintext attack
C Ciphertext-only attack
D Adaptive chosen attack
D
In the process of doing an encryption and decryption, a security engineer steps
away for lunch. While the security engineer was gone, an unsuspecting intruder sat
down at the engineer's desk and ran ciphertext through the crypto device to see the
result. Which attack method best describes this scenario?
A Adaptive chosen attack
B Chosen attack
C Adaptive chosen ciphertext attack
D Chosen ciphertext attack
D
the study of ciphertext, ciphers, and cryptosystems with the aim of understanding
how they work and finding and improving techniques for defeating or weakening
them
cryptanalysis
the process of systematically entering every word in a dictionary as a password to
see if the hashed code matches the one in the password file.
dictionary attack
Which combination of applications mostly uses lightweight cryptography?
A Tablets and RFID
B Servers and RFID
C Desktops and smartphones
D RFID and sensor networks
D
pg. 4
