WGU C839 INTRO TO CRYPTOGRAPHY EXAM QUESTIONS AND
ANSWERS (VERIFIED AND WELL DETAILED ANSWERS) LATEST
UPDATE 2025/2026
What type of encryption uses different keys to encrypt and decrypt the message?
A Symmetric
B Private key
C Secure
D Asymmetric - CORRECT ANSWER D
The most widely used asymmetric encryption algorithm is what?
A RSA
B Vigenere
C DES
D Caesar Cipher - CORRECT ANSWER A
Original, unencrypted information is referred to as ____.
A text
B plaintext
C cleantext
D ciphertext - CORRECT ANSWER B
,Which of the following is NOT an asymmetric system?
A PGP
B RSA
C SSL
D DES - CORRECT ANSWER D
In order for User A to send User B an encrypted message that only User B can
read, User A must encrypt message with which of the following keys?
A User A's public key
B User A's private key
C User B's public key
D User B's private key - CORRECT ANSWER C
The greatest weakness with symmetric algorithms is _____.
A They are less secure than asymmetric
B The problem of key exchange
C They are slower than asymmetric
D The problem of generating keys - CORRECT ANSWER B
Which of the following is generally true about block sizes?
A Smaller block sizes increase security
B Block sizes must be more than 256 bits to be secure
,C Block size is irrelevant to security
D Larger block sizes increase security - CORRECT ANSWER D
A _____ is a function that takes a variable-size input m and returns a fixed-size
string.
A Symmetric cipher
B Hash
C Asymmetric cipher
D Feistel - CORRECT ANSWER B
Which of the following is a cryptographic protocol that allows two parties to
establish a shared key over an insecure channel?
A Elliptic Curve
B RSA
C MD5
D Diffie-Hellman - CORRECT ANSWER D
A _________ is a digital representation of information that identifies you as a
relevant entity by a trusted third party?
A Digital Signature
B Hash
C Ownership stamp
D Digest - CORRECT ANSWER A
, What is the standard used by most digital certificates?
A X.509
B CRL
C RFC 2298
D OCSP - CORRECT ANSWER A
DES uses keys of what size?
A 56 bits
B 192 bits
C 128 bits
D 64 bits - CORRECT ANSWER A
Which of the following is NOT a key size used by AES?
A 512 bits
B 128 bits
C 192 bits
D 256 bits - CORRECT ANSWER A
Which of the following was a multi alphabet cipher widely used from the 16th
century (1553) to the early 20th century (1900s)?
A Vigenere
ANSWERS (VERIFIED AND WELL DETAILED ANSWERS) LATEST
UPDATE 2025/2026
What type of encryption uses different keys to encrypt and decrypt the message?
A Symmetric
B Private key
C Secure
D Asymmetric - CORRECT ANSWER D
The most widely used asymmetric encryption algorithm is what?
A RSA
B Vigenere
C DES
D Caesar Cipher - CORRECT ANSWER A
Original, unencrypted information is referred to as ____.
A text
B plaintext
C cleantext
D ciphertext - CORRECT ANSWER B
,Which of the following is NOT an asymmetric system?
A PGP
B RSA
C SSL
D DES - CORRECT ANSWER D
In order for User A to send User B an encrypted message that only User B can
read, User A must encrypt message with which of the following keys?
A User A's public key
B User A's private key
C User B's public key
D User B's private key - CORRECT ANSWER C
The greatest weakness with symmetric algorithms is _____.
A They are less secure than asymmetric
B The problem of key exchange
C They are slower than asymmetric
D The problem of generating keys - CORRECT ANSWER B
Which of the following is generally true about block sizes?
A Smaller block sizes increase security
B Block sizes must be more than 256 bits to be secure
,C Block size is irrelevant to security
D Larger block sizes increase security - CORRECT ANSWER D
A _____ is a function that takes a variable-size input m and returns a fixed-size
string.
A Symmetric cipher
B Hash
C Asymmetric cipher
D Feistel - CORRECT ANSWER B
Which of the following is a cryptographic protocol that allows two parties to
establish a shared key over an insecure channel?
A Elliptic Curve
B RSA
C MD5
D Diffie-Hellman - CORRECT ANSWER D
A _________ is a digital representation of information that identifies you as a
relevant entity by a trusted third party?
A Digital Signature
B Hash
C Ownership stamp
D Digest - CORRECT ANSWER A
, What is the standard used by most digital certificates?
A X.509
B CRL
C RFC 2298
D OCSP - CORRECT ANSWER A
DES uses keys of what size?
A 56 bits
B 192 bits
C 128 bits
D 64 bits - CORRECT ANSWER A
Which of the following is NOT a key size used by AES?
A 512 bits
B 128 bits
C 192 bits
D 256 bits - CORRECT ANSWER A
Which of the following was a multi alphabet cipher widely used from the 16th
century (1553) to the early 20th century (1900s)?
A Vigenere
