How to Make a Cryptic Code

Cryptic codes are series of letters or other characters with seemingly no meaning, containing a hidden message. This message is only available to those who know the cipher: the specific method to encrypt or decrypt the message. Creating a cryptic code is not difficult; you have to replace ordinary letters, symbols and numbers with other characters. The challenging part of the task, however, is to make the code hard to break by introducing security features, including multiple characters and the ancient Greek method of using a rod -- the "scytale" -- to read the message.

Write down all the letters of the alphabet, numbers from zero to nine and the most common punctuation marks on a piece of notebook paper. Next to each letter, number or symbol place its corresponding character of the code. For example, "C" can become "Γ" and "4" can be "B."

Decide what your secret message will be. Write it out on another piece of paper and then refer to your code list to see what character will replace each letter in your message.

Cut out a 5×5-inch piece of thin cardboard and roll it to form a cylinder. Tape the roll so that it stays rolled up. The cylinder's diameter is extremely important, so use a ruler to measure its exact value. Pass the exact measurements to your friends so that they can make their own cylinders.

Draw a long parallelogram on a piece of letter-size paper. Draw one quarter-inch side at the bottom left corner of the paper and the other quarter-inch side at the top end of the paper, 1/4 of an inch away from the top left corner. Using the ruler, draw long lines to connect the sides and then cut the parallelogram out.

Roll the long strip of paper around the rod so that it spirals down the rod. Write the first character of your secret message at the beginning of the strip, the second character directly below the first character and so forth, so that the list of characters goes down the length of the rod. When you have finished writing the encoded message, unroll the strip.

Fill in the empty sections of the strip with random symbols. Instruct your friends to roll the strip on their special rod and read only the first character and the subsequent characters down the length of the rod.

Make a copy of the cryptic code and give it to your friends. Show them how to use the list to decipher the vertically written message on the rod or to encrypt their own secret message.