Year 7 9 Encryption Vs Decryption Lesson Booklet

Year 7 -9 Encryption Vs Decryption Lesson Booklet Name: Class: Target Level: Assessment Level:

Levels and Targets Before After I Know what encryption and decryption is I can research and names 4 different types of encryptions I know how to use at least one type of encryption to decrypt information I know how to use at least one type of encryption key to encrypt information I can explain the importance of encryption I know who invented the Caesar Cypher encryption method I now know how the Caesar cypher works I can explain the importance of encryption I can explain what Vigenere Cipher I know how to encrypt using Morsecode Cipher Target setting Student Target 1 2 Teacher Target 1 2 Met Not met

Getting started Lesson Objective: Aim: In this lesson you will research the term encryption and decryption and then explain what they mean. You will also research 4 different types of encryption methods that are used to encrypt and decrypt data. Skills List I can now do this (Tick) I can explain what encryption is I now know how the Caesar cypher works I can explain the importance of encryption I can use at least 2 encryption methods to encrypt and decrypt data I know the difference between plaintext and Cipher text Now I want to learn… Because …. . I need more help (Tick)

Bell work What is the difference between encryption and decryption? Answer: Main task Research the following encryption methods and produce a Power. Point to teach year 7 students about how to go about encrypting and decrypting messages Encryption Type Brief description 1: Caesar Cipher 2: Vigenere Cipher 3: Mobile. Phone Cipher 4: Morsecode Review: Write down what you have learned today in 20 words

Caesar Cipher - Notes One of the oldest methods of encryption is the Caesar Cipher. The cipher works by moving each letter in a message forward by a specific number of places in the alphabet. Now watch the video in slide show. To decrypt a message, you need to know how many places each letter was moved. The number of places is called a KEY First wheel: This the original wheel with both big and small wheel aligned Third wheel: The small wheel has been rotated 5 steps forward to Align A with F. The KEY is 5 Second wheel: The small wheel has been rotated 3 steps forward to Align A with D. The KEY is 3 Fourth wheel: The small wheel has been rotated 7 steps forward to Align A with G. The KEY is 7

Encrypt and decrypt all messages below using Caesar Cipher

Objective: Demonstrate New Understanding Bell work Draw this shape without taking your pen off the page and without going over a line you’ve already drawn using free form drawing tool. Answer: Main task : Decrypt these messages: the key is 3. Click and rotate the small wheel inside the bigger wheel to Decrypt each letter 1. EUOSM 2. IVUSR 3. AEYWSRP Review: Write a definition of each word here 1 2 3

Objective: Demonstrate New Understanding Bell work Why do you think encryption is important? Answer: Main task Decrypt these messages: the key is 5 3. EERSDCOOM 3. EARAWLM 3. MLHIROTGA Review: Write a definition of each word here 1 2 3

Objective: Demonstrate New Understanding Bell work Is hacking illegal? Give a reason Answer: Main task Encrypt these messages with the key = 7 1. ICOULDBEASPY 2. DECRYPTTHISHAHA 3. YKCOETPIRN NYE 4. RUOY AAE R RAEKCH Review: Write a definition of each word here 1 2 3

Check your answers Answers Write the Definitions of each word 1. MOUSE 2. VIRUS 3. SPYWARE 4. MORSECODE 5. MALWARE 6. ALGORITHM 7. DECOMPOSITION 8. ENCRYPTION KEY 9. YOU ARE A HACKER

Review and Reflect Encrypt this message below using the key = 5. Then make up your own message for me to decrypt. “Encrypting messages is important because it protects data from unauthorised access. I want to become a ethical hacker!” Click the inside wheel and rotate Type your Encrypted message here

Recap This cipher was invented by Julius Caesar to keep his messages secret. It works by hiding, or “encrypting”, a message by moving each letter a certain number of places to the left in the alphabet. The key tells us how many places forward the numbers have been moved.

Levels and Targets Before After I can explain what encryption is I can explain what decryption is I can name 4 different types of encryption I can encrypt and decrypt data using Cesar cipher I know who invented the Caesar Cypher encryption method I can explain why encryption is important I can explain the difference between plaintext and Cipher text Have you met your targets? Met Student Target 1 2 Teacher Target 1: To explain the importance of strong encryption codes 2: To research who invented Morse code? Not met

Project – Working from Home 1. Research how the 4 Cipher methods work. 2. Create a Power. Point presentation with animation to teach year 7 s how to decrypt and encrypt messaged using all 4 Ciphers 3. Then play the Power. Point game called “Mr Burns” with family to solve a crime USING ALL CIPHER METHODS

Vigenere Ciphers This is similar to the Caesar cipher but harder to decrypt. It converts the letters to numbers and uses a keyword to make it harder! A 0 B 1 C 2 D 3 E 4 F 5 G 6 H 7 I 8 J 9 K 10 L 11 M 12 N 13 O 14 P 15 Q 16 R 17 S 18 T 19 U 20 V 21 W 22 X 23 Y 24 Z 25 Decryption: Example I received the message USDSJFCQNDWCEO and the keyword FOOD. Rules. 1) Write down the encrypted message and convert into numbers underneath U 20 S D S 18 3 J 18 F 9 C 5 2 Q N D 16 13 3 W 22 C E 2 O 4 14 2) Then write down the keyword FOOD repeated underneath the message and convert to numbers underneath make sure they line up F O 5 14 O 14 D 3 F 5 O O D F O 14 14 3 5 14 8 -1 -1 0 3) Now subtract the second row of numbers from the first. 15 4 -11 15 4 -9 -12 13 8 -11 4) Add 26 to negative numbers to get a positive number between 0 -25 15 4 17 14 13 8 15 8 25 25 0 I P I Z A 5) Finally, convert the numbers back to letters. P E Answer P P E R O N PEPPERONIPIZZA when the keyword is FOOD. Z

Mobile Phone Cipher Example 1 A = 2 first position B = 22 move forward 2 positions C = 222 move forward 3 position Example 2 G = 4 first position H = 44 move forward 2 positions I = 444 move forward 3 position

Levels and Targets Before After I can explain what encryption is I can explain what decryption is I can name 4 different types of encryption I can encrypt and decrypt data using Cesar cipher I know who invented the Caesar Cypher encryption method I can explain why encryption is important I can explain the difference between plaintext and Cipher text Have you met your targets? Met Student Target 1 2 Teacher Target 1: To explain the importance of strong encryption codes 2: To research who invented Morse code? Not met

Check for more information and examples in the game “Mr Burns” from Simpson