Lesson Synopsis: Public Key Encryption can be understood as an evolved way to pass secure messages between interested parties while keeping out unwanted snoopers. Let’s dive into the idea of Public Key Encryption of challenging pairs of students in a class to develop ways to communicate securely with each.

Initially, the messages will need to be encoded and decoded at each end. These will be secure, but will they stand the test of the other classmates? Eventually, the recipient’s decoder/encoder will fall into the hands of other students. What can the communicators do to resolve this issue? This opens up the more complex teachable about how Public Key Encryption works.

Depending on the level of students, there’s a possibility for extension and testing with real (simple) mathematical examples. Instruction should include mention of passwords and password security.

Grade: 7th grade and up

Goal: To teach about the importance of encrypting communication, and to teach about how public key encryption keeps messages much more secure than other, simpler methods.

Time: 45 minutes

Context: When we use our computers, we send a lot of information across the wires. Some of this information is material we want to keep private from prying eyes, such as our username and password, our account information for banks, or school applications. Encryption plays a vital role there – why do you think it’s important? Who are we protecting the information against?