Encryption and Code Breaking
Secret codes have been used for thousands of years, particularly in wartime when messages needed to be sent without the enemy being able to understand them if they intercepted them.
The art of writing or solving codes is known as CRYPTOGRAPHY. Many many different codes and ciphers have been created to try and stop people accessing information that they shouldn't. Nowadays we also need to protect data travelling across networks and across the Internet. |
TOP 5 FACTS VIDEO
Watch the video here: www.bbc.co.uk/bitesize/guides/znxxh39/video, and add the top 5 facts about encryption to your notes.
Watch the video here: www.bbc.co.uk/bitesize/guides/znxxh39/video, and add the top 5 facts about encryption to your notes.
Caesar Cipher Tasks
Task 1Download the file linked here and follow the instructions on it.
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Task 2
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Explanation task
Explain means you should give detail in your answer. This means multiple sentences. Use the keywords "alphabet", "shift" and "key".
For question 2, make sure you give your reasons.
For question 2, make sure you give your reasons.
Learn about some other ciphers - read the instructions below!
There are a lot of different ways that data can be scrambled....some methods are easier to decrypt than others. In this activity you are going to learn about a variety of different ciphers and methods of communicating.
This is a good activity to do in a pair using 2 computers - 1 for the research and 1 to enter the answers. Who will be the first to track all the hackers and find the location of the criminal mastermind behind the gang?! Use Google to help you solve the problems. Extension |
The life and work of Alan Turing
Bletchley Park, Alan Turing and the breaking of the Enigma code
During World War 2, Bletchley Park near Milton Keynes became the home of the British code breakers. They worked tirelessly to try and break the German enigma code.
Your task - Create a powerpoint about Alan Turing and Bletchley Park
In YOUR OWN WORDS, explain.....
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How is encryption used today?
Encryption is used to protect information, for example, the messages that you send to your bank that contain your account details. You might also use it to encrypt your messages to friends, or the contents of your computer. It is used by organisations and governments to protect sensitive data and plans.
You might think about encryption as a way of restricting access to data. When data has been encrypted, it is accessible only to those who know how to reverse the encryption process, or decrypt the data. Watch the video below and get ready to answer some final questions. |
Using Python to code the Caesar cipher
Knowledge check!
Code Crackers
Can you employ your knowledge from many Year 8 units to crack the codes?
You'll need to know your Caesar and Pig Pen ciphers and remember how to convert from binary to denary and use an ASCII table. You'll also need to learn some morse code and know how to decrypt the Vigenere cipher. HELP ON THE VIGENERE CIPHER UNDERNEATH THE GAME.
You'll need to know your Caesar and Pig Pen ciphers and remember how to convert from binary to denary and use an ASCII table. You'll also need to learn some morse code and know how to decrypt the Vigenere cipher. HELP ON THE VIGENERE CIPHER UNDERNEATH THE GAME.
The Vigenere cipher |
A Vigenere table |
This is simpler than it looks as it is just a substitution cipher like the Caesar cipher.
You will use a table like the one on the right. You will have a keyword. For example, TURING You will have some cipher text. For example, Vidxhzbhxqflnh To decipher the cipher text: 1. Take the first letter of the keyword. This tells you which row on the table to use. In our example, T is the first letter of the keyword so we use row T first. 2. Take the first letter of the cipher text. In our example, this is V. Using row T find V and then read up to the top of the column. In our example, V becomes C. 3. Take the next letter of the keyword. In our example, this is U. Now use row U to decipher the second letter in the cipher text - i. Using row U i becomes o Repeat this process. When you reach the end of the keyword you simply go back to the beginning and use it again. |