Throughout history, world events have changed because of secret messages. Secrets that were kept and secrets that were not.

In the world of diplomacy, knowing what your enemy is planning helps you to prepare. But it is also important that your enemies do not know what you have planned. It is the mission of the NATIONAL SECURITY AGENCY (NSA) and the CENTRAL SECURITY SERVICE (CSS) to learn what it can about its potential enemies and to protect America's government communications.

In this section, learn about the differences between codes and ciphers, how to make secret ciphers, and what to look for when trying to break a cipher.

What Are Codes?

Although most people think of codes as being secret messages, codes are really any symbol or signal used to represent, or communicate, something else. Any word could be considered a codeword. The code word given to a four-legged furry creature that barks are the letters D, O, G. Because you know that those three letters represent a real dog, you understand the code!

Sometimes, however, it is important that only a few people understand the message. In the world of cryptology, codes are used to make messages secret by changing the words into something else. But, in order for your friends to understand the coded message, they need the key! If your friends have the key, and your enemies do not, your messages become secret.

How well you've created your code and key will determine how long your message stays a secret from others.

Creating a Dictionary Code

Dictionary Codes have been used for centuries. They can be quite confusing to anyone who doesn't know the system - which makes them great for sending secret messages!

DIRECTIONS: Use a dictionary or any book with a lot of different words.

  1. Write down your message in English, this is called "plaintext."
  2. Find the first word in your dictionary or book.
  3. Write down the page number, column or paragraph number, and the Nth word down that column or into that paragraph.
    Example: YOU = Page 1454, Column 1, 24th word down.
  4. Separate the numbers by a period.
  5. Repeat Steps 2-4 for every word in your sentence.
    YOU = 1454.1.24   CAN = 178.1.35   CREATE = 293.1.29
    YOUR = 1454.2.2   OWN = 887.1.16   CODED = 239.2.2D
    MESSAGE = 778.2.20
  6. In some cases, you may have to add a prefix or suffix to the numbers.
    CODED = 239.2.2D
  7. The finished cipher should look like the cipher below.
    1454.1.24  178.1.35  293.1.29 1454.2.2  887.1.16  239.2.2D 778.2.20
    Remember to leave a space between each group of numbers.

You have created your very first code!