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Cryptography Manual

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Cryptography Manual CRYPTOGRAPY MANUAL 1 Pig Latin In words that begin with consonant sounds, the initial consonant or consonant cluster is moved to the end of the word, and "ay" is added, as in the following examples: Happy → appy-hay Pleasant → easant-play For words that begin with a vowel, just add “way” at the end. For example: Apple → apple-way Oink → oink-way 2 Scytale (Pronounced SKEE-tay-LEE) Invented by the Spartans Around the 500 BC so that they could send secret messages They used a stick and parchment – but we can do a simpler version We will need • Cylindrical object (like the cardboard tube found inside of paper towel/toilet paper rolls or even a pen) o Note: The person who you are sending the message to must have the same cylindrical object • Long strip of paper, about 2 cm wide • Something to write with • Tape or blue-tack to fasten the paper to the cylinder How to make A Scytale and encrypt your message 1. Tape one strip of paper to the end of the cardboard tube. 2. Wrap the remaining length of the paper around the tube in a spiral fashion. Make sure that the edges meet without overlapping. Secure the second end of paper to the tube with another piece of tape. 3 3. After the paper is secure, write the message across the strip of paper – just as if you were writing on a normal piece of paper from left to right. Make sure you write one letter per pass of paper. When you reach the end of a line, rotate the scytale slightly away from you and begin the next line of your message. 4. Once the message has been written, unwrap it and you will simply see a bunch of scrambled letters on the paper. Your message has been encrypted! To Decrypt the message Wrap the strip of paper around a scytale of the same size until the letters align and reveal the secret message. 4 The Caesar Shift The Caesar Shift is a substitution cipher and is one of the oldest ciphers spies have ever used. Believe it or not, it was invented by Julius Caesar. In this cipher, one letter is substituted for another letter. To encrypt and decrypt we first need to decide what letters we will be substituting. To do this we take the following steps: Step 1 Write down each letter of the alphabet. This is called a Standard Alphabet. Step 2 Then select a number that will be used as the KEY. For our example, we will use 7 as our Key Number. Step 3 Starting with the letter A in your Standard Alphabet, count seven letters to the right and write the letter A underneath the G. Continue writing the remaining letters of the alphabet until you come to the end of the Standard Alphabet. Step 4 Once you have reached the end of the Standard Alphabet, go back to the beginning and write in the remaining six letters. Now you are ready to encrypt or decrypt Remember, the top alphabet is the Plaintext (The real text) and the bottom is the ciphertext (the message encrypted) 5 The Pigpen cipher The Pigpen Cipher was used by Freemasons in the 18th Century to keep their records private. The cipher does not substitute one letter for another; rather it substitutes each letter for a symbol. The alphabet is written in the grids shown, and then each letter is enciphered by replacing it with a symbol that corresponds to the portion of the pigpen grid that contains the letter. For example: So “Freemasons” would be: 6 The Number Grid This Cipher is very simple; all you need is this grid: To encrypt Begin encrypting your message by locating the first letter of your plaintext message in the grid. Write down the row number followed by the column number. In our example, the T will be encrypted as the number 45. To make your message more secure, leave out the spaces between each word. For example: To Decrypt To begin decrypting the ciphertext, take the first number from the message and examine the number's two digits. The first digit is the row number and the second digit is the column number. 7 The winding way cipher To Encrypt • Count the number of letters used in the message. o Eg: “The new password is enigma” has 22 letters • Create a matrix, or grid, that is large enough to contain your message that has the same number of rows and columns. o Eg our message has 22 letters so we use a grid that is 5x5 • Writing from left to right, fill in the boxes of the matrix. Use an “X” to fill in any remaining boxes in the matrix. T H E N E W P A S S W O R D I S E N I G M A X X X • Draw the pattern below lightly over the matrix and then copy the letters as they appear on the path. TWWSMAEOPHEARNXXIDSNESIGX To Decrypt Using the pattern we used above, put the ciphertext into the grid T T T W W W Etc… Until all the grid has been filled in and the message is visible again. 8 Others There are many other things you can do to disguise your message. For cryptography to be efficient, a person you do not wish to read the message should not be able to understand the message. However, the person who the message is intended for should be able to decode the message easily. Given these rules you can try and come up with some cryptography yourself! Here are some more examples to get you started. Example 1 Why not have numbers be letters, for example: A=1 B=2 C=3 ... Z=26 So hello would be 8 5 12 12 15 Example 2 You could use the letters on a phone keypad to come up with a cipher. So you would get the following table: A=2 B=22 C=222 D=3 ... Z=9999 So hello would be: 44 33 555 555 666 9 Example 3 You could reverse the message in number of ways for example: Reverse in is message this. Is actually: This message is in reverse You don’t have to just reverse the order you can exchange word order or the letter order. May be useful 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 10 .
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