There are 3 different encryption systems here:

- The first is a substitution cypher, each letter is replaced with a different letter. This form of encryption is very easy to crack on any message of a reasonable length.
- The second is in some wasy simpler and in other ways more complex. It is based on a shift cypher, the alphabet is simply shifted a fixed number of characters. Further complexity is added by using several different shifts, how many and how much each one is shifted is determined by a keyword. With a long keyword and a short message this results in a simple but relativly secure code.
- The final code is a very different creature. Rather than simply manipulating the letters in the message this cypher treats the message as a sequence of numbers and performs a seemingly random but repeatable sequence of changes to those numbers. A key number is used to generate the starting point for these calculations. Unlike the previous two systems decryption under this system is achieved by simply encoding the message a second time using the same key. There is also an explanation of why this encryption system works.