WGU C839 EXAM COMPLETE QUESTIONS WITH CORRECT ANSWERS || GRADED A+

WGU C839 EXAM COMPLETE QUESTIONS WITH CORRECT ANSWERS || GRADED A+ .Initializing Vector (Symmetric Algorithm Methods) - Answer--Used with: -Nonce-Generated Initializing Vector -Counter Initializing Vector -Fixed Initializing Vector -Random Initializing Vector - FIPS Standard: - FIPS 180-2: Secure Hash Algorithm (SAH-1) .Cryptography - Answer--Is the study of secure communication mechanisms and methods -Provides ways to encode a message so that it cannot be read by outsiders .Mono-Alphabet Substitution ciphers examples - Answer--AtBash -Ceaser -ROT13 -Scytale .Mono-Alphabet Substitution ciphers definition - Answer--Single Alphabet -Preserve the underlying letter and word frequency and are vulnerable to cryptoanalysis as a result -Frequency analysis can be used to break Mono-Alphabet substitution .Atbash Cipher - Answer--Reverses the alphabet - A becomes Z, B becomes Y ... - Mono-Alphabet Substitution Cipher -Used by ancient Hebrew scholars .Ceasar Cipher - Answer--Choose some number by which to shift each letter of the message - right is "+" and left is "-" - "2" and "1", A becomes C and C becomes B - Mono-Alphabet Substitution Cipher .ROT-13 - Answer--Rotate all charachters 13 letters through the alphabet - A becomes N, B becomes O ... - Mono-Alphabet Substitution Cipher .Scytale Cipher - Answer--A simple transposition cipher -system that employs a rod of a certain thickness around which was wrapped a long, thin strip of parchment. -Uses a rod of certain length to create and encrypt a message -The same rod must be used to read and decrypt the message by the recipient .Multi-Alphabet Substitution Ciphers examples - Answer--The cipher disk -The Vigenere cipher -The Playfair Cipher -The ADFGVX Ciper -The Enigma Machine .Multi-Alphabet Substitution Ciphers definition - Answer--Adds complexity by adding alphabets to be used for the substitution rounds -Example: -We are using three alphabets to do the shifting -Each represented by a "+" or a "-" value -When we run out of of alfahabets, we start over again with the first one, effectivly "round robing" -This is dont through the text until it is all shifted - " A DOG" (+1, -2, +1) - "B BPH" .The Cipher Disk - Answer--Cryptographic device that uses two concentric disks, each with an alphabet around the periphery. -A physical device used to encrypt -Invented by Leon Albert in 1466 -The cipher disk was poly-alphabetic -Each time you turned the disk, you used a different cipher -Multi-Alphabet Substitution Cipher .The Vigenere Cipher - Answer--Invented in 1553 by Giovan Battista Bellaso - It is named for Blasie de Vigenere who deveopled a stronger version cipher -It is a method of encrypting by using a series of interwoven Caesar ciphers based on the letters of a keyword -Poly-alphabetic cipher system -Friedrich Kasiski published the first successful attack against it in 1863 .The Playfair Cipher - Answer--Invented by Charles Wheatstone in 1854 -Uses a 5 x 5 table containing a keyword or key phrase -To generate the key table, one would first fill in the spaces in the table with the letters of the keyword -dropping duplicate letters -Then fill in the remaining spaces with the rest of the letters of the alphabet in order -The technique encrypts pairs of letters -digraphs -Instead of single letters as in the simple substitution cipher -Playfair is significantly harder to break since the frequency analysis used for simple substitution ciphers does not work with it -Any sequence of 25 letters can be used as a key as long as it does not have repeat letters in it .The ADFGVX Cipher - Answer-- The first cipher used by German Army during World War I -Invented by Colonel Fritz Nebel in 1918 -A transposition cipher