WGU C839 Introduction to Cryptography
- (EC-Council CES) Latest 2022
CrypTool ✔✔Software which allows encryption of text using historic algorithms
The Enigma Machine ✔✔In World War II the Germans made use of an electro-mechanical rotor
based cipher Known as The Enigma Machine.
Allied cipher machines used in WWII included the British TypeX and the American SIGABA.
The ADFGVX Cipher ✔✔invented by Colonel Fritz Nebel in 1918.
The key for this algorithm is a six-by-six square of letters, used to encode a 36-letter alphabet.
The Playfair Cipher ✔✔invented in 1854 by Charles Wheatstone.
The Playfair cipher uses a five-by-five table containing a keyword or key phrase.
Breaking the Vigenère Cipher ✔✔In 1863, Friedrich Kasiski was the first person to publish a
successful general attack on the Vigenère Cipher
The Vigenère Cipher ✔✔This is perhaps the most widely known multi-alphabet substitution
cipher. invented in 1553 by Giovan Battista Bellaso. Uses a series of different Caesar ciphers based
on the letters of a keyword.
The Cipher Disk ✔✔The cipher disk was invented by Leon Alberti in 1466. each time you turned
the disk, you used a new cipher. It was literally a disk you turned to encrypt plaintext.
Multi-Alphabet Substitution ✔✔Use of multiple substitution alphabets.
Example:Cipher Disk, Vigenere Cipher, Enigma Machine
Scytale ✔✔This was a cylinder tool used by the Greeks, and is often specifically attributed to the
Spartans. Physical cylinder that was used to encrypt messages.
ROT13 Cipher ✔✔It is essentially the Caesar cipher always using a rotation or shift of 13
characters.
The ATBASH Cipher ✔✔Hebrew scribes copying religious texts used this cipher.
substitutes the first letter of the alphabet for the
last, and the second letter for the second-to-the-last, etc.
The Caesar Cipher ✔✔You can choose to shift any number of letters, either left or right. If you
choose to shift two to
the right, that would be a +2; if you choose to shift four to the left, that would be a -4.
Mono-Alphabet Substitution ✔✔These algorithms
simply substitute one character of cipher text for each character of plain text.
Examples: Atbash Cipher, Caesar Cipher, Rot13
Symmetric Cryptography ✔✔It is simply any algorithm where the key used to decrypt a message
is the same key used to encrypt.
Diffusion ✔✔Changes to one character in the plain text affect multiple characters in the cipher
text.
Confusion ✔✔Confusion attempts to make the relationship between the statistical frequencies of
the cipher text and the actual key as complex as possible. This occurs by using a complex
substitution algorithm.
Avalanche ✔✔a small change yields large effects in the output, This is Fiestel’s variation on
Claude Shannon’s concept of diffusion.
Kerckhoffs’s Principle ✔✔This principle states that a cryptosystem should be secure even if
everything about the system, except the key, is publicly known.
Substitution ✔✔Substitution is changing some part of the plaintext for some matching part of the
Cipher Text.
Transposition ✔✔Transposition is the swapping of blocks of ciphertext.
binary numbers ✔✔there are three operations not found in normal math:
AND, OR, and XOR operations.
Binary AND ✔✔If both numbers have a one in both places, then the resultant number is a one.
1101
1001
1001
Binary OR ✔✔The OR operation checks to see whether there is a one in either or both numbers
in a given place. If so the resulting number is an one.
1101
1001
1101