Secret codes

Want to send secret messages without being caught out. It's so much fun! 

Hide your message behind a mask!

Try this code to send a message that only your best friend can read.

What you'll need

  • Two pieces of paper
  • Pencil
  • Scissors

How to do it...

  1. Put two pieces of paper together and cut identical windows in both to make identical 'masks.'
  2. Mark 'top' on each
  3. Give one to a friend
  4. Put your mask over a blank paper and write your message by placing a word or words in each window.
  5. Remove the mask and add more words to hide your message. (See illustration.)
  6. Your friend can read the message using the other mask. Clever!

Semaphore

Messages sometimes travel between ships by semaphore – a signalling system using two flags. Held in different positions, the flags stand for letters. You can send these signals on paper by drawing stick figures with arms set like the hands of a clock.

What you'll need

  • Two pieces of paper
  • Pencil

How to do it...

  1. 1. Print a copy of this page and give it to your friend.
  2. 2. Study the chart above. Each box shows an alphabet letter, its flag signal, and its symbol.
  3. 3. Think of the message you want to send. Then take a piece of paper and write your message by replacing
    every letter in each word with a flag symbol.
  4. Give your friend the code to work out. Cool or what?!
What does the following message say?

Check your answer at the bottom of the page.

Centimetre words

Use a ruler to make this easy code.

What you'll need

  • A piece of paper
  • Pencil or pen
  • Ruler

    • How to do it...

    1. Lay the ruler across the paper. Print your message in capital letters, placing each letter above the 1cm and 0.5cm marks on the ruler.
    2. Circle the last letter of your message.
    3. Then, to confuse snoopers, fill in other letters between the letters of your message so that they form other words. The words shouldn't have anything to do with the real message.
    4. To read the message, your friend places a ruler under the line of words, with the circle letter over a 1cm or a 0.5cm mark and copies off the letters at each 1cm and 0.5cm interval. You’re super-sleuths now!

    Scrambled letters

    Send a secret code that involves scrambling letters in the alphabet.

    What you'll need

  • A piece of paper
  • Pencil or pen

    • How to do it...

    1. Cut a paper rectangle and a strip that slides through it. (See the picture above.)
    2. Write the alphabet from A to Z on the rectangle and write it twice from Z to A on the strip. (See the picture above.)
    3. Space both alphabets alike. Choose a key letter and position it beneath the A. Use letters on the strip to spell out the message. Sneaky!

    Number switch

    Send a secret code that involves substituting letters for numbers.

    What you'll need

  • A piece of paper
  • Pencil

    • How to do it...

    1. 1. To make an easy number cipher, substitute a number for every letter in the alphabet. Begin with number one for the letter A.
    2. For a different number cipher, put the alphabet in a box (See the picture above.) Put either I and J or Y and Z together in one box. Write each letter as a double number: A=11, B=12, C=13, and so on. Now that’s a tricky one!

    Build a pig pen or a box

    Soldiers once used pigpens to send secret messages.

    What you'll need

    • One or two pieces of paper
    • Pencil

    How to do it...

    Pigpen

    1. A typical pigpen substitutes a symbol for each letter. Look at segment 1 in the picture above. The shape of the 'pen' that encloses each letter forms a different symbol. Letter E, for example, has the symbol .

    2. Try reading the code written in segment 1.

    Route cipher
    1. Route ciphers put messages in boxes. See segment 3 in the picture above. To make a route cipher, mark your 'route' in a blank box. Give a copy of the marked box to your friend.
    2. Write your message in the box so it follows the route. For a long message, use two boxes. Copy the letters, a row at a time, top row first, left to right.
    3. Your friend will put the letters in a box in the same order, then read the message by following your route.
    4. Another route cipher is shown in segment 2 in the picture above. Read the cipher from bottom to top in each row. What does it say?

    Fold some paper

    You can hide a message just by folding paper. Try the two ways shown here.

    What you'll need

    • One or two pieces of paper
    • Pencil

    How to do it...

    1. Fold one paper in half. Then fold the halves back to make quarters.
    2. Write the message so the words read across the panels. Jumble the message with extra words.
    3. You can also fold a piece of paper into quarters and write a vertical message on the creases. (See the pictures at left.) Then add a false message around the real one. Genius!

     

    Answers: Semaphore: Send a secret message. Route cipher: Enemy coming. Send more men now.

    Text: NG Kids staff. Illustrations: Barbara L. Gibson