Caesar Ciphers, Enigma and Steganography

The past couple of weeks have been busy!  There are seven different classes in the Gifted Program.  Though they are all working on the same theme, Top Secret Communication, each class is doing slightly different activities depending on the age and interests of the students.  Here are some of the things we have been doing in the past few weeks.

Caesar Ciphers

All of the classes have made their own Caesar Cipher Wheels and have been busy encrypting and decrypting messages.  Students in grades 3 - 5 have all become quite adept at decrypting Caesar cipher messages, even if they haven't been given the key!  One letter words are a big tip off, since they can only be the words/letters "a" or "I".  If there are no one letter words, have no fear!  The students know to look for three letter words that are repeated (as they may represent "the" or "and").  Words with contractions (such as "I'm", "can't" or "she's") are also helpful in breaking Caesar Ciphers as the final letter is usually "m", "t", or "s".

Caesar Cipher Wheel

A wonderful website that the Wednesday and Thursday morning grade 5s have been exploring is the Crypto Club site.  It has tools to help you encipher and decipher messages using a variety of ciphers, including the Caesar Cipher that we have been using.  It also has some fun challenges and games for students to try out.

The Enigma Machine

A student from the Tuesday morning grade 3-4 class brought in her Pocket Enigma, which led to an exploration of the history of the Enigma Machine, how it worked, and the staggering number of possible settings for it.  In many of the classes we have watched this video (or will be watching it soon) on the history and mathematics of the Enigma machine.

Steganography

Steganography, as the Wednesday afternoon grade 1-2 class can tell you, is hidden or concealed writing.  This past week the grade 1-2 class explored steganography as we experimented with invisible inks.  Students painted pictures or messages using lemon juice, milk, vinegar, tonic water, and Tide or baking soda (both diluted in water).  After the paintings had dried we revealed the hidden images/words by using heat (on the lemon juice and milk), painting over them with red cabbage juice (on the lemon juice, vinegar, and baking soda) or by shining a UV light on them (for the tonic water and Tide).  

The Wrap Up

These are just a few of the things the students have been doing.  In the weeks ahead we will continue to explore ciphers and code making and breaking as well as looking at non-verbal communication.