I have a BUNCH of nieces and nephews. Over the years, doing some secret message passing with them around birthdays and holidays has been fun. The “secret” location of hidden Christmas presents is a favorite. Traditionally, we’ve used a transposition cipher like the Shift or Ceasar Cipher For something different, we’re going to use another transposition cipher called the Rail Fence Cipher. It is easy to implement and understand. Plus easy to break, so it’s a good teaching tool.