← Revision N5 Computing Science  ·  James Gillespie's
CS  ·  Revision  ·  Section D

Protect It or Save Energy?
Environment and Security Drill

Computer Systems revision Approx 25–35 min 6 scenarios  ·  justification practice
Recap: A firewall checks the data coming into and leaving a network and blocks traffic that breaks its rules (e.g. from unknown addresses). Encryption scrambles data with a key so that it cannot be understood if it is intercepted or stolen. Computers affect the environment through their energy use and through e-waste when devices are thrown away.  → Full lesson: CS9 — Environmental Impact and Security
How to use this drill: Choose the precaution or the environmental action that fits each scenario, then justify it with a detail from the scenario. Reveal the model answer to check your reasoning.
Your choices and justifications are saved automatically.
Section D — Environmental Impact and Security

6 scenarios. Choose an answer, justify it using the scenario, then check the model answer. Scenario 6 is marked DISCUSS — either answer can be correct if well justified.

Scenario 1 of 6 Unknown visitors

A school wants to stop computers on the internet that it does not recognise from connecting to the computers on its network.

Expected: Firewall A firewall. It checks incoming traffic against a set of rules and blocks connections from addresses that are not allowed, protecting the computers inside the school network.
Scenario 2 of 6 Paying online

A customer types their bank card details into an online shop. The details travel across the internet to the shop's server.

Expected: Encryption Encryption. The card details are scrambled before they are sent, so if they are intercepted on the way across the internet they cannot be read without the key.
Scenario 3 of 6 Stolen laptop

A doctor's laptop holds patient files. If it is stolen, the thief must not be able to read the files.

Expected: Encryption Encryption. A firewall protects a network connection, but it does nothing once someone has the laptop. Encrypting the files means they cannot be understood without the key, even if the thief has the laptop.
Scenario 4 of 6 Overnight computers

A school's 200 computers are left switched on every night and every weekend.

Expected: Reduce energy use Reduce energy use. The computers use electricity when nobody is using them. Switching them off, or using power-saving settings such as sleep mode, reduces energy use, carbon emissions and cost.
Scenario 5 of 6 New phones every year

A company gives every employee a new smartphone every year and throws the old ones away, even though they still work.

Expected: Reduce e-waste Reduce e-waste. Throwing away working devices creates electronic waste, which can contain harmful materials. Keeping devices for longer, refurbishing or reusing them, and recycling them properly all reduce e-waste.
Scenario 6 of 6 Hospital records Discuss

Two hospitals send patient records to each other over the internet. Each hospital also has its own network that hackers try to break into.

Expected: Either — if justified using the scenario If choosing Encryption: the records travel across the internet, so they should be encrypted so that anyone who intercepts them cannot read them.

If choosing Firewall: hackers are trying to get into each hospital's network, so a firewall should block connections that are not allowed.

Exam note: both precautions apply to different parts of the scenario. Encryption protects data in transit; a firewall protects the network. Say which threat your choice deals with.
Marker's eye view — why candidates lose marks

The classic error is saying a firewall "stops viruses" or "protects data". Be precise: a firewall filters network traffic using rules. Encryption does not stop data being intercepted — it makes intercepted data unreadable without the key.

For environmental impact, give the action and its effect, e.g. "switch computers off overnight, which reduces energy use". Naming just "energy" or "recycling" usually earns only half the marks.