deCIPHERing Codes in the Classroom

Do you ever do things in your classroom just to throw your students off balance a little and get their attention? I admit that I think it is kind of fun to watch student’s reactions when I try something totally new in class and they aren’t quite sure what to think. Although the topic of codes and ciphers is different and cool in its own right, you can make it even more engaging for students by immersing students in the subject from the beginning of the lesson.

I considered encrypting this entire post using a cipher, but luckily for you, I didn’t! It might be fun to have students decode something at the beginning of a lesson, though or to encode the solution to a problem to make it very secretive. Have you ever been in a foreign language class where there is no English allowed in the classroom? The same idea could work well here. What if a whole lesson depended on students to crack a code to get started? If you want your students to dig deep and figure out how encryption, codes, and ciphers have worked in the past and how they work in current applications such as internet security, they need to experience this type of encryption and decoding first hand.

To better understand codes and ciphers, read Joann’s post on the topic here. The following definitions might also be helpful. According to Merriam-Webster’s Student Dictionary, a cipher is a “method of changing a message so as to conceal its meaning” or “a message in code.” A code is defined as “a system of symbols (as letters or numbers) used to represent assigned and often secret meanings.” Simplifying it a little more, one NOVA resource explains that codes are “letter combinations or symbols used to represent words or concepts” (think Morse code or police codes like 10-4) while a cipher is “a message in which letters or symbols replace actual letters in the message” (it looks like nonsense until you figure out the key.)

Doesn’t it all sound so cool and spy-like? Joann’s post introduces this topic in its pure form: learning about codes and ciphers for the sake of learning about codes and ciphers. The lessons she features will teach students to encrypt and decode messages, useful knowledge for the “real world.” This can easily be worked into a history, math, or technology class. With a little planning, this theme can also be used to bring interest to completely unrelated topics of study.

You can let your students practice decoding a simple cipher online. It looks complicated, but there is a hints section that helped me a lot. In the end, solving this cipher was a lot like a giant Wheel of Fortune puzzle, and the secret message was pretty funny. I think older students working in pairs or groups would do well with this.

A neat thing about ciphers is that you can encode just about anything you want. Once students decode one puzzle, they will have a “key” so they can encode their own. To make your own cipher, think of what you want your students to decode first. It could be the directions for an activity, a passage to discuss, a story problem…the possibilities are endless! There are lots of ways you can encrypt this message. To choose your method, consider the skill level of your students and whether or not they will have computer access.

If your students will be working with pen and paper, you can find different ciphers to use that you can print out and give to them. Two famous historical ciphers are a cipher from Thomas Jefferson and a cipher used by the Navajo Code Talkers. You can find information about these ciphers as part of lesson plans on Education World here and here. You may not decide to follow the plans for either lesson, but I thought the printable ciphers would be very useful. One resource that has quite a few ciphers to try comes from the Exploratorium site. You should definitely be able to find some good ciphers here! This link is temporary and we will be adding it to the Gateway library soon.

NOVA created a neat online tool using the Enigma cipher, a cipher machine that looks something like a typewriter. When using this machine, the person encrypting and decoding would both need the same three-letter code and access to an Enigma machine. The explanation of the Enigma and how it works is fascinating. To see the tool, go here. Using this tool, you and your students can encrypt and decode all kinds of messages and send them to one another through email. I was planning to encrypt a whole paragraph for you here, so you could try it out, but it proved to be a little more complicated than I thought. I would recommend using the tool for shorter (maybe one sentence) blurbs. Be sure to try it on your computer before presenting to your class, as I had a little trouble with the Macromedia Shockwave plug-in.

I hope you can each find ways to integrate codes and ciphers into your teaching. It’s an easy way to add an exciting twist to your lessons. We are always looking for quality resources to add to the Gateway, so please let us know if you find any you like better.