1. Making and decoding a code message

2. Making a coded message Decide on a message Decide on a key word
Form a matrix using the key word repeated over and over. Number of row sufficient to cover the number of letters in the message.
Make a matrix using the message. Fill the end in with 0s.
Add the matrixes' together and rewrite the message.

3. Alphabet numbering

4. Example1
Message – Making codes is fun and easy to do. (13,1,11,9,14,7,0,3,15,4,5,19,0,9,19,0,6,21,14,0,1,14,4,5,1,19,25,0,20,15,0,4,15)
Key word – cough (3,15,21,7,8)

5. Add the two matrixes and rewrite the message

6. The message sent is
16, 16, 32, 16, 22, 10, 15, 24, 22, 12, 8, 34, 21, 16, 27, 3, 21, 42, 21, 8, 4, 29, 25, 7, 13, 4, 34, 46, 7, 28, 18, 15, 25, 22, 8
From Cough

7. Decoding the message
Start by finding the dimensions of the two matrixes.
Subtract the two matrixes.
Substitute the letters for your new numbers.

8. Since cough is five letters then both matrixes are going to be something by five 16, 16, 32, 16, 22, 10, 15, 24, 22, 12, 8, 34, 21, 16, 27, 3, 21, 42, 21, 8, 4, 29, 25, 7, 13, 4, 34, 46, 7, 28, 18, 15, 25, 22, 8 Cough , 15, 21, 7, 8

9. Subtract the two matrixes
13,1,11,9,14,7,0,3,15,4,5,19,0,9,19,0,6,21,14,0,1,14,4,5,1,19,25,0,20,15,0,4,15
Making codes is fun and easy to do

10. 45, 38, 26, 14, 39, 33, 35, 44, 17, 18, 20, 27, 25, 23, 21, 32, 35, 46, 24, 23, 25, 22, 21, 45, 20, 48, 20, 35, 20, 28, 21, 37, 5, 33, 35, 37, 42, 28, 5, 34, 28, 34, 39, 23, 8, 29, 24, 30 From Twenty