WGU Course C839 - Intro to Cryptography Latest 2026 Update||
Questions and Correct Verified Answers /C839 Already Graded
A+ Brand New!!!
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
A
What is the standard used by most digital certificates?
A X.509
B CRL
C RFC 2298
D OCSP
A
DES uses keys of what size?
A 56 bits
B 192 bits
C 128 bits
D 64 bits
A
Which of the following is NOT a key size used by AES?
A 512 bits
B 128 bits
C 192 bits
pg. 1
,D 256 bits
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
B Caesar
C Atbash
D Scytale
A
Which of the following is a substitution cipher used by ancient
Hebrew scholars?
A Caesar
B Vigenere
C Scytale
D Atbash
D
Shifting each letter in the alphabet a fixed number of spaces to the
right or left is an example of what?
A Bit shifting
B Confusion
C Multi substitution
D Single substitution
D
Which of the following most accurately defines encryption?
A changing a message so it can only be easily read by the intended
recipient
pg. 2
,B Making binary changes to a message to conceal it
C changing a message using complex mathematics
D Applying keys to plain text
A
If you use substitution alone, what weakness is present in the resulting
cipher text?
A It is the same length as the original text
B It is easily broken with modern computers.
C It is too simple.
D Because it maintains letter and word frequency.
D
_____ uses at least two different shifts, changing the shift with
different letters in the plain text.
A Atbash
B multi-alphabet encryption
C Scytale
D Caesar cipher
B
____ was designed to provide built in cryptography for the clipper
chip.
A Blowfish
B Skipjack
C GOST
D 3DES
B
Which of the following uses an 80 bit key on 64 bit blocks?
pg. 3
, A Twofish
B AES
C Skipjack
D DES
C
With _____, the message is divided into blocks and each block is
encrypted separately. This is the most basic mode for symmetric
encryption.
A Electronic codebook (ECB)
B Cipher-block chaining (CBC)
C Cipher feedback (CFB)
D Output feedback (OFB)
A
Which of the following is an example of an unbalanced Feistel?
A 3DES
B Skipjack
C Twofish
D AES
B
This process is done by having each block of plaintext is XORed with
the previous ciphertext block before being encrypted.
A Output feedback (OFB)
B Cipher-block chaining (CBC)
C Electronic codebook (ECB)
D Cipher feedback (CFB)
B
pg. 4
Questions and Correct Verified Answers /C839 Already Graded
A+ Brand New!!!
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
A
What is the standard used by most digital certificates?
A X.509
B CRL
C RFC 2298
D OCSP
A
DES uses keys of what size?
A 56 bits
B 192 bits
C 128 bits
D 64 bits
A
Which of the following is NOT a key size used by AES?
A 512 bits
B 128 bits
C 192 bits
pg. 1
,D 256 bits
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
B Caesar
C Atbash
D Scytale
A
Which of the following is a substitution cipher used by ancient
Hebrew scholars?
A Caesar
B Vigenere
C Scytale
D Atbash
D
Shifting each letter in the alphabet a fixed number of spaces to the
right or left is an example of what?
A Bit shifting
B Confusion
C Multi substitution
D Single substitution
D
Which of the following most accurately defines encryption?
A changing a message so it can only be easily read by the intended
recipient
pg. 2
,B Making binary changes to a message to conceal it
C changing a message using complex mathematics
D Applying keys to plain text
A
If you use substitution alone, what weakness is present in the resulting
cipher text?
A It is the same length as the original text
B It is easily broken with modern computers.
C It is too simple.
D Because it maintains letter and word frequency.
D
_____ uses at least two different shifts, changing the shift with
different letters in the plain text.
A Atbash
B multi-alphabet encryption
C Scytale
D Caesar cipher
B
____ was designed to provide built in cryptography for the clipper
chip.
A Blowfish
B Skipjack
C GOST
D 3DES
B
Which of the following uses an 80 bit key on 64 bit blocks?
pg. 3
, A Twofish
B AES
C Skipjack
D DES
C
With _____, the message is divided into blocks and each block is
encrypted separately. This is the most basic mode for symmetric
encryption.
A Electronic codebook (ECB)
B Cipher-block chaining (CBC)
C Cipher feedback (CFB)
D Output feedback (OFB)
A
Which of the following is an example of an unbalanced Feistel?
A 3DES
B Skipjack
C Twofish
D AES
B
This process is done by having each block of plaintext is XORed with
the previous ciphertext block before being encrypted.
A Output feedback (OFB)
B Cipher-block chaining (CBC)
C Electronic codebook (ECB)
D Cipher feedback (CFB)
B
pg. 4
