The ICT Lounge
Section 8.8:
Encryption is used as a security measure that makes data un-readable even if it is stolen.

In this section we discuss
encryption and why it is used.
Key Concepts of this section:
Understand what encryption is.
Be able to describe why it is important to encrypt personal or sensitive data.

Encrypting data
Key Words:
Encryption Key, Encrypt, Decrypt.
What is encryption?
Whenever you use a computer device that is connected to the internet, you are potentially vulnerable to hackers.

Encryption locks data and stops it from being read by unauthorised people.
Encryption turns data into scrambled and unreadable nonsense.
Encryption keys are used to encrypt (lock) and decrypt (unlock) files and data.
(Click image to zoom)
Word documents can be encrypted.
Medical records can be encrypted.
Email messages can be encrypted.
In fact, you can encrypt any type of computer data.
Historical Encryption

People have always looked for ways to keep their messages secret:

Julius Caesar communicated battle plans with his generals in code.

Mary Queen of Scot’s plans to take the English throne from Queen Elizabeth were hidden in code.

Both the Allies and the Germans transmitted messages in code. They also both tried to devise devices that could break the coded messages.
Hackers will try and break into your computer in order to steal personal information like social security numbers and bank/credit card details.

Hackers want this data so that they can commit identity fraud or steal your cash.

In section 8.3, we discussed methods that we can use to help prevent hackers from breaking into a computer system.

We talked about the following authentication techniques:
  • User-Id's and Passwords
  • Biometrics (eye scans, fingerprint scans etc.).
If these authentication techniques fail and a hacker breaks into the system, encryption is another layer of defense for our personal data.

Encryption works by scrambling data into garbled code using an encryption key.

Even if data is stolen, it cannot be understood by the thief.

Only authorised people who have the decryption key will be able to unscramble the data and read it.

Encryption doesn’t actually prevent hackers from accessing the data.

It just stops them from being able to read or use it.

An example of encryption:
Nick wants to send a personal message to Pauline.

Nick wants to encrypt the message so that it can only be read by Pauline.

The example below explains how the encryption process works:

Encrypting a file:
Nick first needs to create an encryption key.

The key will usually be a very long random number.
Nick will now give Pauline a copy of the
encryption key.
Nick can now encrypt (lock) the personal message using encryption software and the encryption key.
Once encrypted, the message will just look like scrambled nonsense.
Nick can now send the encrypted message to Pauline via the internet.
No one can read the message without the encryption key. Even if a hacker intercepts it, all they will see is the garbled nonsense that encryption generated.
When Pauline receives the message, she will use her copy of the encryption key to decrypt (unlock) the message.
Pauline can now read the message sent by The Nick.

When should you use encryption?
It is a good idea to use encryption and stop unauthorised people from reading your data in the following circumstances:
  • Any files containing bank account or credit card data
  • When buying items on the internet using credit/bank cards
  • Any data containing confidential medial records
  • Emails that you wish to remain private
  • Any data that could be used to commit identity fraud (social security numbers, insurance numbers etc.).

Some videos:
Here are some links to videos that contain more information about encryption:



Click the above task and answer the questions about encryption.


Please add your questions/comments below:

Links to Theory Units:
Links to Practical Units:
Section 11: File Management
Section 12: Images
Section 13: layout
Section 14: Styles
Section 15: Proofing
Section 16: Graphs and Charts
Section 17: Document Production
Section 18: Data Manipulation
Section 19: Presentations
Section 20: Data Analysis
Section 21: Website Authoring