Make A Cipher: Caesar's Shift Cipher

How to Encrypt a Caesar's Cipher

Step 1
Write down each letter of the alphabet. This is called a Standard Alphabet.


Then select a number that will be used as the KEY.


For our example, we will use 7 as our Key Number.


Step 2
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 3
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 your message!


Step 4
Locate the first letter from your plaintext in the Standard Alphabet. The letter below it is the cipher letter. Follow this method for each letter.


For example: B=V, I=C, O=I


Step 5
There are many different kinds of Caesar Ciphers, or Shift Ciphers, as they are commonly called.


Try using shifted numbers or a key word cipher instead of letters for your next secret message!



CONGRATULATIONS! 
You have created a Number Shift Cipher!

Read More

Make A Cipher: Number Shift Cipher

How to Encrypt a Number Shift Cipher

Step 1
Write down your PLAINTEXT message on a piece of paper.


Step 2
Create a 5x5 grid, also known as a Polybius Grid, on your paper.


Make sure your grid has 25 squares when you are finished.


Step 3
Write the numbers 1 thru 5 down the left side of the grid and across the top of the grid as well.


Beginning with the letter A, fill in the squares with the letters of the alphabet. Because there are only 25 squares, cryptanalysts usually put the letters Y and Z together in the last square.


Step 4
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.


Step 5
Continue until your entire message has been encrypted.


To make your message more secure, leave out the spaces between each word.

CONGRATULATIONS! 
You have created a Number Shift Cipher!

How to Decrypt a Number Shift Cipher

Step 1
Based on the KEY provided by the sender, create a 5x5 grid (Polybius Grid). Label the rows 1 thru 5 down the left side of the grid and the columns 1 thru 5 across the top.


Step 2
Once you have created the grid, fill in the squares with the letters of the alphabet. Because there are only 25 squares and 26 letters, remember to put Y and Z in the same square at the bottom of the grid.


Step 3
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.


Write the letter that appears at the intersection of the specific row and column on the grid.


Step 4
Continue decrypting the ciphertext until your message is revealed.

CONGRATULATIONS! 
You have learned how to decrypt a Number Shift Cipher!

Read More

Make A Cipher: One Pig's Pen

How to Encrypt a Pig Pen Cipher

Step 1
Write down your PLAINTEXT message on a piece of paper. Then draw two tic-tac-toe grids and two big X's - alternating each grid as you draw them on your paper.


Step 2
In the last two grids, place a dot in each compartment.


Then, beginning with the first grid, fill in each compartment with a single letter of the alphabet.


Step 3
To draw the cipher letters, use the shape of the compartment, or the "pen," surrounding the letter itself.


DO NOT include the letter in the cipher.


Step 4
Once you have created the cipher, send the message to a friend. Before you send it, make sure your friend knows what the patterns are for the grids and letters.


To make the cipher more secure, try changing the letter and dot patterns inside the compartments.

How to Decrypt a Pig Pen Cipher

Step 1
Arrange the grids and letters on a piece of paper according to the KEY that breaks the cipher.


Draw the grids in the correct pattern and then fill in the different compartments, or pens, with the appropriate dots and letters.


Step 2
Begin decrypting the message by comparing the shape of each cipher letter with the shape of the grid compartments.


Once you find a match, write down the letter that the cipher represents. Continue until you have completed decrypting the entire message.

Read More

Make A Cipher: The Key

How to Encrypt a Key Cipher

Step 1
Choose a word to be your KEY word. Make sure the word you select has at least five or six letters in it and has no repeating letters. For example the word APPLE will not work with this cipher because there are two P's in the word. In our example, we will use the word MAPLE for our key.


Step 2
Write the Key word on a piece of paper. Leave a little bit of space between each letter as you write down each letter of your Key.


Next, draw a column under each letter of the Key word.


Step 3
Fill in the columns by writing your PLAINTEXT message one letter at a time.


Any empty spaces should be filled in with a NULL. A NULL is usually represented by the letter X.


Step 4
Rewrite the columns so that the letters in your Key word are in alphabetical order.


In our example, the word MAPLE will be rearranged to read AELMP.


Step 5
To see your encrypted message, copy the letters in each column from top to bottom, but DO NOT include the letters in the Key word.

CONGRATULATIONS!
You have successfully created a KEY CIPHER!

How to Decrypt a Key Cipher

Step 1
Find out what the KEY word is from the person who sent you the message. Write the letters from the Key word in alphabetical order on a piece of paper.


Draw a column under each letter of the Key word.


Step 2
Starting under the letter A and writing from left to right, fill in the grid with the letters from the ciphertext.


Step 3 
Once the grid is filled in, rearrange the columns so the Key word is spelled out correctly. Reading from left to right, you should be able to see the plaintext message.

CONGRATULATIONS! 
You have successfully deciphered a KEY CIPHER!

Read More