Cryptology and Cybersecurity for Young Scholars ~ Part One: The History of Codes and Ciphers

This is the first in a series of posts related to the study of CRYPTOLOGY for advanced students in grades 3-5. See also Part Two: Crack the Code! ~ FIND A VIRTUAL SLIDE SHOW READY-TO-SHARE WITH STUDENTS HERE!

Here’s a unit of study that incorporates math, science, history, engineering and also involves solving puzzles! No wonder kids love CRYPTOLOGY! People of all ages are fascinated by codes and ciphers and their history and uses today.

Certainly, many students are familiar with the different types of codes used in our everyday lives including barcodes, computer codes, passwords, PINs, QR codes, and VPNs (virtual private networks). In many schools, basic computer coding skills are now introduced to all students. However, students are not usually aware of how codes have been developed to solve various problems. A comprehensive study of cryptology will engage students in thinking about the role of codes and ciphers over time and possible uses in the future.

INTRODUCING THE UNIT

Cryptology is included in the fourth-grade thematic study of MYSTERIES and unanswered questions. Here are some activities you can use to introduce the mini-unit.

(1) “One-Two-Four” BRAINSTORMING ~ Have students brainstorm everything they associate with the word CODE, including types of codes and all the different ways codes are used in today’s world. “One-Two-Four” brainstorming means students begin by making their own list, independently. After a few minutes, students merge lists with a partner, and then as a group of four, discuss and add to their lists.

(2) Spend a few minutes introducing the LANGUAGE of the DISCIPLINE. Here is a slide show you can use that incorporates the etymologies of the most basic terms used in cryptology. Make your own copy HERE.

(2) Share the message shown below and ask students to try to decipher it. Allow some time, but students may give up fairly quickly. Explain that the cipher was developed by the ancient Greeks for military purposes. It’s a transposition cipher; ask students to use what they learned about the language of the discipline to determine what that could mean.

LCNEN 51784LWPHE 51962AOLDS

To decipher the message, both the sender and the recipient needed a cylindrical baton called a scytale (pronounced by some with a silent “c” in the first syllable, like “psy” in “psychology;” others say “skit-uh-lee.”). The scytale used by the recipient had to have the same diameter as the one used by the sender of the message.

For this quick hands-on simulation, students will use a “fat” glue stick (approximately 1.25″ in diameter) as their scytale. Provide wide-ruled notebook paper and large glue sticks. Have students cut the top, bottom, and side margins off of the paper, copy the code down the page, then trim to create a strip (see photo). Explain that the message is encrypted by writing the letters from top to bottom. Demonstrate how to wrap the paper strip around the glue stick so that the lines on the paper are aligned. When completely wrapped around, the message can be decrypted by turning the scytale horizontally and reading from left to right, bottom to top. The message is “SEND HELP NOW. CALL 264-987-1155.”

In addition to adding a fun, hands-on introduction to the unit, this activity provides a lead into the video excerpts below; this particular cipher and its history will be further explained.

(3) Give this “guessing game” PRE-TEST (you can make your own copy HERE), then show video clips one at a time (your copy HERE) so that students can check their guesses. [Note: the video is no longer available on YouTube, so you have to use timings to show the excerpts that correspond with the pretest]. This is a quick way to share some of the fascinating ways codes and ciphers have been created and used throughout history. The video, in its entirety, can be found HERE, but I only used excerpts in my classroom.

These are just a few introductory activities you can use with your students. Part Two: Crack the Code! introduces various types of codes. If you’d like to be notified when additions to this series are made, consider subscribing for regular updates. And, as always, we’d love your comments below if you try these activities or if you have additional ideas to share!