Encryption
Overview
Every time you log in to a bank or send a message, your data travels across networks where it could be intercepted. Encryption is the lock that keeps that data meaningless to anyone who steals it on the way. It does not stop a thief grabbing the data, it makes the stolen data useless.
In this lesson you will learn why encryption is needed, the difference between scrambled cipher text and readable plain text, and the two methods you must be able to describe: symmetric encryption, which shares one secret key, and asymmetric encryption, which uses a clever public and private key pair to keep the secret safe even on the open internet.
Objectives
- 1 Understand the need for and purpose of encryption when transmitting data
- 2 Understand how data is encrypted using symmetric and asymmetric encryption
Audio Lesson
Listen to this lesson in the app
Mind map
This topic is mapped out so you can see how the ideas connect.
Open the mind map in the app
Flashcards
Quick recall practice on the facts this topic is tested on.
Practise these cards in the app
Lesson Note
Complete Note Available on the Green Bridge App
Get the Green Bridge CBT app on your phone or computer for the complete IGCSE library: past papers, mark schemes, mind maps, flashcards and audio lessons.
Lesson Evaluation
Congratulations on completing the lesson on Encryption. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- What is the name given to data after it has been encrypted? A. plain text B. cipher text C. metadata D. payload Answer: B
- Symmetric encryption uses: A. no key B. a public and a private key C. the same key to encrypt and decrypt D. two public keys Answer: C
- Which statement about encryption is correct? A. it stops a hacker stealing data B. it makes stolen data meaningless C. it deletes intercepted data D. it speeds up transmission Answer: B
- In asymmetric encryption, which key decrypts data sent to you? A. your public key B. your private key C. the sender's private key D. a shared key Answer: B
- Why is asymmetric encryption considered more secure for internet use? A. it uses shorter keys B. the decryption key is never transmitted C. it does not need a key D. it is faster Answer: B
Work through these questions in the app
Work through these questions in the app
Recommended Books
Practice Mock Questions
Want to practice mock questions on Encryption? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in your exams
