What does a firewall do?

checks incoming and outgoing traffic against a set of rules. Traffic that breaks the rules is blocked.

Which is an example of biometric authentication?

a fingerprint scan. Biometrics use a feature of the person's body.

What is two-step verification?

needing a second check, such as a code sent to a phone, as well as a password. A stolen password alone is not enough.

Why should software updates be automated?

so that fixes for security weaknesses are installed promptly. Out-of-date software has known weaknesses.

What does a proxy server do?

sits between the user and the internet, hiding the user's IP address. It can also filter the traffic passing through.

What do access levels do?

give different users different rights to data. People can reach only what they need.

encrypts data sent between a browser and a web server. It is a security protocol.

Keeping data safe · Cambridge IGCSE Computer Science (9

In plain words

There is no single lock that keeps data safe. Protection comes in layers: checking who someone is, limiting what they can do, watching what comes in and out, and teaching people to notice when something is wrong.

8 things to know

Authentication checks that users are who they say they are: a username and password, biometrics (such as a fingerprint or face), or two-step verification, where a code sent to a phone or email is needed as well as the password.
Access levels give different users different rights, so each person can see and change only the data they need.
Anti-malware software, including anti-virus and anti-spyware, scans files, compares them with a database of known malware, and removes or quarantines anything it finds.
A firewall checks the traffic coming into and going out of a network or computer against a set of rules, and blocks anything that does not meet them.
Automating software updates means that fixes for security weaknesses are installed as soon as they are released.
Checking the spelling and tone of a message, and checking the URL attached to a link, helps a user to spot a phishing attempt.
A proxy server sits between a user and the internet. It hides the user's IP address and can filter traffic. Privacy settings control who can see a user's information.
Secure socket layer (SSL) is a security protocol that encrypts the data sent between a browser and a web server.

Worked example

A company wants to stop its staff's accounts being broken into, even if a password is stolen. What should it use?

A stolen password is enough to log in if a password is all that is needed.
Two-step verification adds a second check: a code sent to the user's own phone.
An attacker with only the password cannot get the code, so cannot log in.

Tips and tricks

Match the defence to the threat. Anti-malware for viruses. A firewall for unauthorised traffic. Checking URLs for phishing. Encryption for interception.
A firewall does not remove viruses, and anti-virus software does not block network traffic. Keep their jobs apart.

7 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

Keeping data safe: 7 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 a firewall do?
- removes viruses from files
- checks incoming and outgoing traffic against a set of rules (the answer)
- encrypts every file on a disk
- backs up data
Traffic that breaks the rules is blocked.
Which is an example of biometric authentication?
- a password
- a PIN
- a fingerprint scan (the answer)
- a username
Biometrics use a feature of the person's body.
What is two-step verification?
- typing a password twice
- needing a second check, such as a code sent to a phone, as well as a password (the answer)
- having two passwords
- logging in on two computers
A stolen password alone is not enough.
Why should software updates be automated?
- to use more storage
- so that fixes for security weaknesses are installed promptly (the answer)
- to change how the screen looks
- to slow down attackers' computers
Out-of-date software has known weaknesses.
What does a proxy server do?
- stores the user's passwords
- sits between the user and the internet, hiding the user's IP address (the answer)
- prints documents
- creates viruses
It can also filter the traffic passing through.
What do access levels do?
- make the network faster
- give different users different rights to data (the answer)
- encrypt emails
- detect viruses
People can reach only what they need.
What does SSL do?
- scans for malware
- encrypts data sent between a browser and a web server (the answer)
- blocks adverts
- stores cookies
It is a security protocol.

7 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.

Keeping data safe

Cambridge IGCSE Computer Science (9–1) 0984 · 6 marks · papermunch.org

Name ______________________________ Date ______________

Describe how a firewall helps to keep data safe.[2]
Show answerHide answer
It examines the traffic coming into and going out of a network. It blocks any traffic that does not meet its rules.
I got this one
Explain how two-step verification makes an account more secure.[2]
Show answerHide answer
The user needs something as well as the password, such as a code sent to their phone. Someone who has stolen the password cannot log in without it.
I got this one
Give two things a user could check to decide whether an email is a phishing attempt.[2]
Show answerHide answer
The spelling and tone of the message. The URL that the link in the message leads to.
I got this one

Answers: Keeping data safe

1. It examines the traffic coming into and going out of a network. It blocks any traffic that does not meet its rules.
2. The user needs something as well as the password, such as a code sent to their phone. Someone who has stolen the password cannot log in without it.
3. The spelling and tone of the message. The URL that the link in the message leads to.