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WGU C839 OA AND PRE-ASSESSMENT NEWEST 2025
TEST BANK| INTRO TO CRYPTOG RAPHY EXAM
WITH COMPLETE 400 ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) GRADED A+ (BRAND NEW!!)
WGU C839 OBJECTIVE ASSESSMENT
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 B Caesar C Atbash D Scytale - Correct Answer - A
Which of the following is a substitution cipher used by ancient Hebrew scholars?A Caesar B Vigenere 1 / 4
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pg. 2 C Scytale D Atbash - Correct Answer - 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 - Correct Answer - 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 - Correct Answer - B
____ was designed to provide built in cryptography for the clipper chip.A Blowfish B Skipjack
C GOST
D 3DES - Correct Answer - B
Which of the following uses an 80 bit key on 64 bit blocks? 2 / 4
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pg. 3 A Twofish B AES C Skipjack D DES - Correct Answer - 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) - Correct Answer - A
Which of the following is an example of an unbalanced Feistel?
A 3DES
B Skipjack C Twofish D AES - Correct Answer - 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) 3 / 4
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pg. 4 D Cipher feedback (CFB) - Correct Answer - B
The process wherein the ciphertext block is encrypted then the ciphertext produced is XOR'd back with the plaintext to produce the current ciphertext block is called what?A Output feedback (OFB) B Cipher-block chaining (CBC) C Cipher feedback (CFB) D Electronic codebook (ECB) - Correct Answer - C
This is a method for turning a block cipher into a stream cipher by generating a keystream block, which are then XORed with the plaintext blocks to get the ciphertext.A Cipher feedback (CFB) B Electronic codebook (ECB) C Output feedback (OFB) D Cipher-block chaining (CBC) - Correct Answer - C
A fixed-size pseudorandom number that is fed into a symmetric cipher to increase randomness is called what?
A IV B Key C Chain D Salt - Correct Answer - A
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