How to Encrypt a Rail Fence Cipher

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

Then write each letter of the plaintext on two separate lines - the first letter goes on the first line, the second on the second line, the third letter goes back on the first line, and so on.

Step 2
Count the total number of letters used.

The total number of letters should equal a multiple of 4 (8, 12, 16, 20). If not, you will need to add extra letters, called NULLS, until it is a multiple of 4.

Step 3
Beginning with Line 1, combine the letters from both lines to create your CIPHERTEXT.

Divide the letters into as many groups as you like.

CONGRATULATIONS! You have successfully created a RAIL FENCE CIPHER!

How to Decrypt a Rail Fence Cipher

Step 1
Divide the letters in half by drawing a line through the ciphertext.

Write the first half of the message on one line and the second half on a new line beneath it. Make sure you leave a space between each letter.

Step 2
Rewrite the message by combining letters from Line 1 and Line 2.

Make sure that you alternate between lines and leave out any NULLS that are included at the end.

CONGRATULATIONS! You have successfully deciphered a RAIL FENCE CIPHER!