Computer Science (0984) 2023 - 2 Data Transmission 2-3

2-3 Encryption

• Encryption is the process of encoding data or a message so that it cannot be understood by anyone other than its intended recipient.
• Encryption does not prevent someone from intercepting a message - instead it prevents them from being able to understand it.
• Unencrypted messages are referred to as plain text messages. 
• Encrypted messages are known as ciphertext.
  

2-3-1 Understand the need for and purpose of encryption when transmitting data

• Encryption is used to ensure that data can be stored and messages can be sent securely over a network.
  • Online purchases
  • Encrypting documents that are private
  • Satellite TV transmissions prevent non-subscribers from watching TV shows

2-3-2 Understand how data is encrypted using symmetric…