What does encryption do?

makes data unreadable without the key. Stolen data is useless to the thief.

What is the purpose of a firewall?

to control the traffic between a network and the internet. It blocks traffic that breaks its rules.

Which is an example of two-factor authentication?

a password followed by a code sent to a phone. Two different kinds of proof are needed.

What does a digital certificate prove?

that a website is genuine. It is issued by a trusted authority.

What does SSL provide?

an encrypted link between a web server and a browser. Data sent between them cannot be read by others.

How can you tell that a website uses a secure connection?

The address starts with https and a padlock is shown. The s stands for secure.

Protecting data · Cambridge IGCSE Information & Communication Technology

In plain words

No single lock protects data. A system is made safe by layers: proving who you are, scrambling the data, guarding the network's door, and proving that a website is what it claims to be.

7 things to know

A user ID and password: the ID says who you are and the password proves it. Access is refused if they do not match, and the account is usually locked after several wrong attempts.
Biometrics use a physical feature such as a fingerprint, face or iris. The feature is scanned and compared with the stored biometric data.
Two-factor authentication needs two different proofs, for example a password and then a code sent to the user's phone. A stolen password is not enough to get in.
Encryption scrambles data so that it is unreadable without the key. It protects data on hard discs, in emails, in the cloud and on HTTPS websites. It does not stop data being stolen: it makes stolen data useless.
A firewall sits between a computer or network and the internet. It checks incoming and outgoing traffic against a set of rules and blocks what is not allowed.
Secure socket layer (SSL) creates an encrypted link between a web server and the user's browser, so that data sent between them cannot be read.
A digital certificate proves that a website is genuine. It contains details such as the owner's name, the public key, the issuer, a serial number and an expiry date.

Worked example

A customer is about to type card details into a shopping website. How can she tell the connection is secure?

The address begins with https, not http.
The browser shows a padlock symbol.
These show that the site has a digital certificate and that data sent to it is encrypted.

Tips and tricks

Encryption does not prevent hacking or interception. Always say what it does do: makes the data unreadable without the key.
Two-factor means two different kinds of proof. Two passwords are not two factors.

6 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

Protecting data: 6 questions and answers

These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.

What does encryption do?
- stops data being intercepted
- makes data unreadable without the key (the answer)
- deletes data
- compresses data
Stolen data is useless to the thief.
What is the purpose of a firewall?
- to cool the computer
- to control the traffic between a network and the internet (the answer)
- to back up files
- to speed up downloads
It blocks traffic that breaks its rules.
Which is an example of two-factor authentication?
- typing a password twice
- using a long password
- a password followed by a code sent to a phone (the answer)
- two people sharing one login
Two different kinds of proof are needed.
What does a digital certificate prove?
- that a file has no viruses
- that a website is genuine (the answer)
- that a password is strong
- that a computer is switched on
It is issued by a trusted authority.
What does SSL provide?
- a backup of a website
- an encrypted link between a web server and a browser (the answer)
- a faster connection
- free storage
Data sent between them cannot be read by others.
How can you tell that a website uses a secure connection?
- The page loads slowly.
- The address starts with https and a padlock is shown. (the answer)
- The site has many pictures.
- The address ends in .com.
The s stands for secure.

6 questions

Tap an answer and you’ll see straight away whether it’s right, and why.

Worksheet

3 questions, 6 marks. Write your answers on paper, then check them.

Protecting data

Cambridge IGCSE Information & Communication Technology 0417 · 6 marks · papermunch.org

Name ______________________________ Date ______________

Explain the purpose of a firewall.[2]
Show answerHide answer
It monitors the traffic coming into and going out of a network or computer. It blocks traffic that does not meet its rules, such as attempts at unauthorised access.
I got this one
Explain how two-factor authentication increases security.[2]
Show answerHide answer
The user must give two different proofs of identity, such as a password and a code sent to their phone. Someone who has stolen the password still cannot log in.
I got this one
State two items contained in a digital certificate.[2]
Show answerHide answer
The name of the owner and the public key. (Also: the issuer, a serial number, the expiry date.)
I got this one

Answers: Protecting data

1. It monitors the traffic coming into and going out of a network or computer. It blocks traffic that does not meet its rules, such as attempts at unauthorised access.
2. The user must give two different proofs of identity, such as a password and a code sent to their phone. Someone who has stolen the password still cannot log in.
3. The name of the owner and the public key. (Also: the issuer, a serial number, the expiry date.)