This unplugged lesson will allow students to encrypt and decrypt message using the Caesar Cipher letter shift method of encryption. Cover the process of how this method works by doing an example and explaining the process of shifting the plaintext by the letter shift value to create the encrypted cipher text.

This lesson is designed to teach students basic encryption using the Caesar cipher method. This is a simple letter shift cipher that takes a plaintext message and encrypts it into cipher text by shifting each letter of the message by a value between 1 and 25 (1 less than the total number of letters in the English alphabet). This technique was used by Julius Caesar to encrypt messages by shifting each letter of the message by 3 letters. The message would be decrypted by taking each letter and shifting back 3 letters to reveal the plaintext message.

This lesson plan can be used for teaching and reinforcing the idea of encryption for middle school students.

The student or class will watch a video clip about how to decode a Vigenère Square Cipher.Next students will be able to use the cipher to crack a secret message of their own (teacher provided messages in a hat (not inlcuded)).  One student chooses the word or phrase, the teacher puts the key (word) on the board, that same student will encrypt the message and send it to their partner.  The partner with use the same key word to return the text to plain text revealing the message and send their guess back to their partner. Teachers can edit the message to fit their needs and make adjustments as desired.  This is one mini lesson out of a series of five (part 2) and can be used alone, or with other lessons in the series. Vigenère Square Ciphefrom the past.  Next students will be able to use a Pigpen cipher to crack a secret message of their own.  Teachers can edit the message to fit their needs and make adjustments as desired.  This is one mini lesson out of a series of five. Vigenère Square Ciphe

The student will watch a brief video about the first Morse Code ever sent and how it impacted American communications, even today.  Students will be able to decipher a short Morse Code code (SOS).  They will also learn about Kryptos, an artwork that contains four secretive messages and is placed on display outside of the CIA headquarters. 

The student or class will read about book ciphers and how they work.  Students will then be able to use a cipher provided to crack a secret message.  Teachers can edit the message to fit their needs and make adjustments as desired.  This is one mini lesson out of a series of five, this is lesson four and it can be completed alone, or with any of the other lessons.

The student or class will watch a video clip about ciphers, specifically Caesar Ciphers.  Next students will learn more about encryption and decryption through the use of "keys".  Lastly, students will be introduced to the career path choices as a Cyber-security analyst. This is one lesson out of a series of five, and can be used alone, or with the some or all of the other four lessons.

This is an introductory lesson on encryption and decryption. It includes a discussion about the importance of protecting data when communicating across a network. The data is protected through a process of encryption and decryption.Students are asked to decrypt a message (in this case, a scientific fact to reinforce knowledge ) using the encrypted message and a decryption key.

This is an introductory lesson on encryption and decryption. It includes a discussion about the importance of protecting data when communicating across a network. The data is protected through a process of encryption and decryption.Students are asked to decrypt a message (in this case, a scientific fact to reinforce knowledge ) using the encrypted message and a decryption key.

This activity is from the Cyber.org website and covers the topic of the German Enigma Encryption machine that was used during World War II. Students will learn about how the Enigma machine worked and the process it used to encrypt messages. Students will be able to create their own Enigma machine using a normal size Pringles can and the activity sheet in PDF format. This is a great way to teach the concepts of encryption and a low cost way to give students a hands on approach to encrypting and decrypting messages.Ideas on how to use this activity would be to give the students a message to encrypt using their Pringles can Enigma machine or having students send an encrypted message to a classmate with the encryption key and have that student decrypt the message. To show the power of this type of encryption you can have other students try to decrypt the message without the key so they can see how difficult it would have been to crack the code during World War II.Link to the Cyber.org website for this activity

This lesson is presented by Code.org
Lesson 8: Cybersecurity - Simple Encryption

From the website:
OVERVIEW
"In this lesson, students are introduced to the need for encryption and simple techniques for breaking (or cracking) secret messages. Students try their own hand at cracking a message encoded with the classic Caesar cipher and also a Random Substitution Cipher. Students should become well-acquainted with idea that in an age of powerful computational tools, techniques of encryption will need to be more sophisticated. The most important aspect of this lesson is to understand how and why encryption plays a role in all of our lives every day on the Internet, and that making good encryption is not trivial. Students will get their feet wet with understanding the considerations that must go into making strong encryption in the face of powerful computational tools that can be used to crack it. The need for secrecy when sending bits over the Internet is important for anyone using the Internet."

OBJECTIVE
"Explain why encryption is an important need for everyday life on the Internet.
Crack a message encrypted with a Caesar cipher using a Caesar Cipher Widget
Crack a message encrypted with random substitution using Frequency Analysis
Explain the weaknesses and security flaws of substitution ciphers"

The lesson is mapped out for teachers. It is easy to follow and includes vocabulary to cover, links to the necessary materials, and a teaching guide with background information, tips, and prompts.

AGENDA
Warm Up (10 min)
Classic Encryption - The Caesar Cipher
Activity (35 min)
Part 1 - Crack a Caesar Cipher
Part 2 - Crack a Random Substitution Cipher
Wrap Up (15 min)
Video: Encryption and Public Keys
Discussion
Career Discussion

Overview: This lesson is presented by Code.org
Lesson 8: Cybersecurity - Simple Encryption

From the website:
OVERVIEW
"In this lesson, students are introduced to the need for encryption and simple techniques for breaking (or cracking) secret messages. Students try their own hand at cracking a message encoded with the classic Caesar cipher and also a Random Substitution Cipher. Students should become well-acquainted with idea that in an age of powerful computational tools, techniques of encryption will need to be more sophisticated. The most important aspect of this lesson is to understand how and why encryption plays a role in all of our lives every day on the Internet, and that making good encryption is not trivial. Students will get their feet wet with understanding the considerations that must go into making strong encryption in the face of powerful computational tools that can be used to crack it. The need for secrecy when sending bits over the Internet is important for anyone using the Internet."

OBJECTIVE
"Explain why encryption is an important need for everyday life on the Internet.
Crack a message encrypted with a Caesar cipher using a Caesar Cipher Widget
Crack a message encrypted with random substitution using Frequency Analysis
Explain the weaknesses and security flaws of substitution ciphers"

The lesson is mapped out for teachers. It is easy to follow and includes vocabulary to cover, links to the necessary materials, and a teaching guide with background information, tips, and prompts.

AGENDA
Warm Up (10 min)
Classic Encryption - The Caesar Cipher

Activity (35 min)
Part 1 - Crack a Caesar Cipher
Part 2 - Crack a Random Substitution Cipher

Wrap Up (15 min)
Video: Encryption and Public Keys
Discussion
Career Discussion

***This lesson can be adapted for younger students but material covered aligns best with the current 8th grade Impacts of Computing Standards.