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WGU C839 Introductory Cryptography Exam
– Actual Test with Complete 200 Questions and
Verified Detailed Answers, Recently Released
Official Exam Overview:
The WGU C839 OA assesses learners’ comprehension of cryptography principles, including public
key infrastructure (PKI), encryption techniques, certificates, and key management. The exam
emphasizes the ability to explain cryptographic components, manage digital certificates, and
apply PKI policies to ensure secure communications and data integrity across IT systems.
Exam Coverage Areas:
• Public Key Infrastructure (PKI) concepts and components
• Certificate management and policy frameworks
• Symmetric and asymmetric encryption fundamentals
• Digital signatures and authentication mechanisms
• Key generation, storage, and distribution
• Cryptographic protocols for secure data exchange
• Practical application of cryptography in IT security
QUESTION 1:
Which part of the public key infrastructure (PKI) defines how a credential is used?
A) Certificate authority (CA)
B) Certificate policy (CP) ✅
C) Registration authority (RA)
D) Certificate revocation list (CRL)
Rationale:
A Certificate Policy (CP) specifies the rules and guidelines for how a certificate or credential
may be used, defining its scope, limitations, and applicability in PKI operations.
QUESTION 2:
Which PKI component is responsible for issuing and signing digital certificates?
A) Registration Authority (RA)
B) Certificate Authority (CA) ✅
C) Certificate Policy (CP)
D) Public Key Repository
,Rationale:
The Certificate Authority (CA) issues, signs, and manages certificates, establishing trust within
the PKI environment.
QUESTION 3:
Which PKI element verifies the identity of a user or entity before issuing a certificate?
A) Certificate Policy (CP)
B) Registration Authority (RA) ✅
C) Certificate Authority (CA)
D) Key escrow system
Rationale:
The Registration Authority (RA) handles identity verification and certificate requests, ensuring
only authorized users receive credentials.
QUESTION 4:
Which PKI component provides a mechanism to revoke compromised or invalid certificates?
A) Certificate Policy
B) Certificate Revocation List (CRL) ✅
C) Registration Authority
D) Public Key Repository
Rationale:
A CRL lists certificates that have been revoked before their expiration, allowing systems to reject
compromised or invalid credentials.
QUESTION 5:
Why is a certificate policy important in PKI?
A) It defines encryption algorithms
B) It specifies acceptable uses of certificates ✅
C) It stores private keys
D) It issues digital signatures
Rationale:
A certificate policy ensures consistent and secure use of credentials, defining the conditions,
limitations, and obligations for certificate usage in the network.
Which part of the public key infrastructure (PKI) defines how a credential is used? - ANSWER-
Certificate policy (CP)
,Which part of the public key infrastructure (PKI) is used to ensure that the format for a
credential can be used by anyone on the internet? - ANSWER-Public Key Cryptography
Standards (PKCS)
Which solution is used in a Layer 2 Tunneling Protocol (L2TP) virtual private network (VPN) to
secure data in transmission? - ANSWER-Internet Protocol Security (IPsec)
Which network-based virtual private network (VPN) prevents unauthorized logins by preventing
packet retransmission? - ANSWER-IP security (IPsec)
Which port does Secure Socket Tunneling Protocol (SSTP) use? - ANSWER-Port 443
What is a common problem with using pre-shared keys (PSKs)? - ANSWER-Secure key exchange
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What is a concern with storing long-term secrets on media or memory? - ANSWER-Integrity
Which cipher uses a series of ciphers based on a keyword? - ANSWER-Vigenère
Which substitution cipher system reverses the sequence of the alphabet? - ANSWER-Atbash
Which type of cipher converts a letter to a number, passes it through a mathematical function,
and then converts it back to a letter? - ANSWER-Affine
Which technique solves polyalphabetic substitution ciphers by deducing the key length? -
ANSWER-Kasiski's method
Which cryptanalysis technique examines ciphertext for recurring letter combinations? -
ANSWER-Frequency analysis
Which cryptanalysis method involves a person being tricked into encrypting a set of known
messages? - ANSWER-Chosen plaintext attack
Which technique does related-key cryptanalysis use to decipher a message? - ANSWER-
Messages are encrypted using different secrets, and the analyst compares the messages to
figure out how the algorithm works.
2
WGU C839 Introductory Cryptography Exam
– Actual Test with Complete 200 Questions and
Verified Detailed Answers, Recently Released
Official Exam Overview:
The WGU C839 OA assesses learners’ comprehension of cryptography principles, including public
key infrastructure (PKI), encryption techniques, certificates, and key management. The exam
emphasizes the ability to explain cryptographic components, manage digital certificates, and
apply PKI policies to ensure secure communications and data integrity across IT systems.
Exam Coverage Areas:
• Public Key Infrastructure (PKI) concepts and components
• Certificate management and policy frameworks
• Symmetric and asymmetric encryption fundamentals
• Digital signatures and authentication mechanisms
• Key generation, storage, and distribution
• Cryptographic protocols for secure data exchange
• Practical application of cryptography in IT security
QUESTION 1:
Which part of the public key infrastructure (PKI) defines how a credential is used?
A) Certificate authority (CA)
B) Certificate policy (CP) ✅
C) Registration authority (RA)
D) Certificate revocation list (CRL)
Rationale:
A Certificate Policy (CP) specifies the rules and guidelines for how a certificate or credential
may be used, defining its scope, limitations, and applicability in PKI operations.
QUESTION 2:
Which PKI component is responsible for issuing and signing digital certificates?
A) Registration Authority (RA)
B) Certificate Authority (CA) ✅
C) Certificate Policy (CP)
D) Public Key Repository
,Rationale:
The Certificate Authority (CA) issues, signs, and manages certificates, establishing trust within
the PKI environment.
QUESTION 3:
Which PKI element verifies the identity of a user or entity before issuing a certificate?
A) Certificate Policy (CP)
B) Registration Authority (RA) ✅
C) Certificate Authority (CA)
D) Key escrow system
Rationale:
The Registration Authority (RA) handles identity verification and certificate requests, ensuring
only authorized users receive credentials.
QUESTION 4:
Which PKI component provides a mechanism to revoke compromised or invalid certificates?
A) Certificate Policy
B) Certificate Revocation List (CRL) ✅
C) Registration Authority
D) Public Key Repository
Rationale:
A CRL lists certificates that have been revoked before their expiration, allowing systems to reject
compromised or invalid credentials.
QUESTION 5:
Why is a certificate policy important in PKI?
A) It defines encryption algorithms
B) It specifies acceptable uses of certificates ✅
C) It stores private keys
D) It issues digital signatures
Rationale:
A certificate policy ensures consistent and secure use of credentials, defining the conditions,
limitations, and obligations for certificate usage in the network.
Which part of the public key infrastructure (PKI) defines how a credential is used? - ANSWER-
Certificate policy (CP)
,Which part of the public key infrastructure (PKI) is used to ensure that the format for a
credential can be used by anyone on the internet? - ANSWER-Public Key Cryptography
Standards (PKCS)
Which solution is used in a Layer 2 Tunneling Protocol (L2TP) virtual private network (VPN) to
secure data in transmission? - ANSWER-Internet Protocol Security (IPsec)
Which network-based virtual private network (VPN) prevents unauthorized logins by preventing
packet retransmission? - ANSWER-IP security (IPsec)
Which port does Secure Socket Tunneling Protocol (SSTP) use? - ANSWER-Port 443
What is a common problem with using pre-shared keys (PSKs)? - ANSWER-Secure key exchange
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, Page 2 of 39
What is a concern with storing long-term secrets on media or memory? - ANSWER-Integrity
Which cipher uses a series of ciphers based on a keyword? - ANSWER-Vigenère
Which substitution cipher system reverses the sequence of the alphabet? - ANSWER-Atbash
Which type of cipher converts a letter to a number, passes it through a mathematical function,
and then converts it back to a letter? - ANSWER-Affine
Which technique solves polyalphabetic substitution ciphers by deducing the key length? -
ANSWER-Kasiski's method
Which cryptanalysis technique examines ciphertext for recurring letter combinations? -
ANSWER-Frequency analysis
Which cryptanalysis method involves a person being tricked into encrypting a set of known
messages? - ANSWER-Chosen plaintext attack
Which technique does related-key cryptanalysis use to decipher a message? - ANSWER-
Messages are encrypted using different secrets, and the analyst compares the messages to
figure out how the algorithm works.
2
