Cryptography Murder Mystery

I love starting a new semester with a group worthy task that gets students up and moving. It allows me to get a great feel for my new students and how they interact with their peers. It also provides them with something exciting and different than they standard syllabus introduction to a course.

This task was designed to introduce a mini unit on computer science but it could easily be used in any science or math class. After all, science and math are all about discovering and interpreting patterns to make conclusions

Many thanks to interactive-maths.com and the crypto corner resources that inspired much of this activity

Task Overview

• 30-40 minutes
• Cryptography and Pattern Finding

Lesson Plan - Cryptography Murder Mystery
File Size:	636 kb
File Type:	pdf

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Introduction

I did not spend much time introducing this task. Since it was the first day of the semester, I did a quick introduction of myself and talked about the importance of patterns in science. This video from Khan Academy served as a really nice simple introduction to the world of cryptography before passing out the clues and letting groups get started.

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The Task

This challenge is based off of the game Clue where players need to identify a murder suspect, location, and weapon. There are 6 options given for each category and every clue that a group deciphers will narrow that list down. As written, groups will need to solve all 8 clues before they are able to solve the mystery.

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The Clues

Each of the clues is encoded using a different cipher technique. Each of these techniques are outlined in the resource posters shared below. None of these ciphers are too intense and the keys are given when needed so students should be able decrypt the messages without having to employ frequency analysis or other more advanced cryptography techniques. One of the biggest challenges for the students is that even though the resource posters provide the information about each cipher, it isn't always obvious which cipher to use for a particular clue.

Cryptography Clues (pdf)
File Size:	689 kb
File Type:	pdf

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Cryptography Clues (editable)
File Size:	69 kb
File Type:	pptx

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Cryptography Resources

I wanted students to teach themselves the necessary skills to decode these messages. To facilitate this, I created standalone posters that provide students with all of the resources they need even if they don't have any background in cryptography techniques. I printed these posters and hung them up around the room. From these, students should be able to decode any of the secret messages. I encouraged my students to walk around the room and take photos of the posters so they could bring these resources back to their group.

Cryptography Resources (pdf)
File Size:	880 kb
File Type:	pdf

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Cryptography Resources (editable)
File Size:	164 kb
File Type:	pptx

Download File

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Solutions

I highly recommend that you try this task for yourself first before looking at the solutions. You will have a much better idea of the process to help your students through if you have gone through it beginning to end from their point of view. That said, it is really handy to have a page with all of the solutions to have with you as you walk around during the task. These solutions contain the clue number, cipher used, and encoded message for each of the 8 clues. They are also color coded to indicate whether they are information about the suspect, location, or weapon.

Cryptography Solutions (pdf)
File Size:	244 kb
File Type:	pdf

Download File

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Wrap Up

As I mentioned earlier, this task was used to kick off a mini unit on computer science that we tried this year in 9th Grade Physical Science. Cryptography isn't just an engaging way to introduce the theme but it is also a very relevant topic in the field of computer science. From Turing's machine that helped crack the Enigma Cipher to end World War II to the exciting advances today in Bitcoin and Blockchain technologies, cryptography is a huge part of our history and our present. This video from SciShow does a great job highlighting some of these impacts. I just showed the last couple minutes (starting at 5:58) to focus on the applications but the whole video is really interesting and well made.

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Files

Below are the files for the posters and clues. Please use and share freely for non-commercial purposes. If you have any questions or ideas, leave a comment below :)

Cryptography Clues (pdf)
File Size:	689 kb
File Type:	pdf

Download File

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Cryptography Clues (editable)
File Size:	69 kb
File Type:	pptx

Download File

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Cryptography Solutions (pdf)
File Size:	244 kb
File Type:	pdf

Download File

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Cryptography Resources (pdf)
File Size:	244 kb
File Type:	pdf

Download File

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Cryptography Resources (editable)
File Size:	164 kb
File Type:	pptx

Download File

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Cryptography Lesson Plan (pdf)
File Size:	636 kb
File Type:	pdf

Download File

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Cryptography Lesson Plan (editable)
File Size:	25 kb
File Type:	docx

Download File

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Below you will find a .zip file of the digital (PDF and editable) files needed for this cryptography murder mystery task. All of the files are included individually in the sections above as well but it's nice to get everything in one tidy package!

Cryptography Murder Mystery.zip
File Size:	2525 kb
File Type:	zip

Download File

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