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

C839 Introduction to Cryptography| WGU C839|
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130 QUESTIONS| WITH COMPLETE SOLUTIONS
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A typical use is digital signatures.
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One way. You cannot "un-
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hash" something. Collision resistant.
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SAM file - ANS- g g g


File in the Windows System directory where hashed passwords ar
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e stored.
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salt - ANS-random bits that are used as one of the inputs to the hash.
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MD5 - ANS- g g


128 bit hash, specified by RFC 1321 not collision
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resistant.
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Flaw found in 1996
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MD6 - ANS-Uses a Merkle Tree-
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like structure to allow for immense parallel computations of hashe
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s for very long inputs. Submitted in the NIST SHA-3 competition
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SHA-1 - ANS-A hash function that creates a 160-
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bit message digest.
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SHA-2 - ANS- g g


A family of Secure Hash Algorithms that has variations, known as
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SHA-224, SHA-256, SHA-384, and SHA-512. g g g g




SHA-3 - ANS- g g


Proposed hash function standard still in development.
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,FORK-256 - ANS-Hash g g




uses 512- g


bit blocks and implements preset constants that change after ea
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ch repetition. Each block is hashed into a 256-
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bit block through four branches that divides each 512 block into s
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ixteen 32-bit words that are further encrypted and rearranged
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RIPEMD-160 - ANS- g g


A message digest algorithm that produces a 160-
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bit hash value after performing 160 rounds of computations on 51
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2-bit blocks. g




GOST - ANS-Hash algorithm which produces a fixed-
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length output of 256 bit blocks.
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Tiger - ANS- g g


A hash function with a hash value of 192 bits. Uses the Merk
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le-Damgard construction g




Merkle-Damgard construction - ANS-Method to build collision- g g g g g g


gresistant cryptographic hash functions from collision-
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resistant one-way compression functions.
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MAC - ANS- g g


Message Authentication Code. Uses a block cipher in CBC mode to
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improve integrity. g




HMAC - ANS- g g


Hash Message Authentication Code. Adds a key to a hash to improv
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e integrity.
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,CBC-MAC - ANS- g g


Turns a block cipher into a MAC. Encrypts the message using CBC
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mode, then discards all but the last block of ciphertext.
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, Cryptography - ANS- g g


The science of altering communication so that it cannot be underst
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ood without having the key.
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cipher - ANS- g g


The algorithm(s) needed to encrypt and decrypt a message.
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Mono-alphabet substitution - ANS- g g g


Substitute one character of cipher text for each character of plain t
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ext.

Caesar cipher - ANS- g g g


Every letter is shifted a fixed number of spaces to the left or the righ
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t in the alphabet.
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Ciphertext - ANS- g g


The resultant text after being subjected to the algorithm and key.
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Atbash Cipher - ANS- g g g


Reverses the alphabet ( A becomes Z, B becomes Y ... ) - Mono-
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Alphabet Substitution Cipher. Hebrew code.
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Affine Cipher - ANS- g g g


single substitution cipher. Each letter is mapped to a numerical valu
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e, permuted with a math function and then converted back to a lette
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r.

Affine cipher formula - ANS-ax + b (mod M)
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ROT13 - ANS- g g