Key number method

The 'Key Number' method is a theory of simple cryptography. It is based around exchanging every letter of the alphabet for a set number, usually A=1, B=2 etc. or sometimes A=26, Z=1 etc., and then having a 'Key Number' that you use to encrypt the letters. For example, let's say that our message is 'hello'. It would be represented like this: 8 5 12 12 15. The key number will be 5. The key number is placed in front of the message, (5 8 5 12 12 15) and then you add up each number with the number that comes after it. This gives you the finished encryption: 13 13 17 24 27. To DECODE it, you need to know the key number, and the method of representing the numbers. Spaces are usually left out, but can be represented with an extra space. Punctation is often represented normally, or just full stops, which are represented by a vertical line: |.