What it shows
Apps on a phone are checked for the permissions they hold, such as camera, microphone and location, and compared with what they need. It teaches how to protect privacy by limiting access.
The science
Apps ask for permissions to use sensors and data on the phone. A torch app does not need your contacts, and a calculator does not need your location. Giving only the permissions that a task really needs is called the principle of least privilege. Many phones also let you allow a permission only while the app is in use or ask each time.
Materials
Cost: free. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- A family phone with its owner’s permission and a parent or teacher present
- The phone’s Settings page for Apps and Permissions or Privacy
- A spreadsheet program: LibreOffice Calc (free) or Google Sheets (free)
- A notebook and a pencil
Safety
For this project: Only audit a phone with its owner’s agreement and an adult present. Do not change settings on a phone you do not own, and do not note down any passwords or personal data.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Ask the owner for permission, then open Settings and find the Permissions manager or Privacy section on the phone.
Choose ten apps and write their names in the first column of a table, and add columns Camera, Microphone, Location, Contacts and Storage.
For each app enter Yes if the permission is allowed and No if not, by tapping each app in the permissions list.
Add a column Needed? and decide with the owner whether the app really needs each permission it has.
Count with =COUNTIF(B2:F11,"Yes") how many permissions are allowed in total.
With the owner’s agreement change unnecessary permissions to Deny or While using the app, and write what changed.
Check that the apps still work for what the owner needs; restore a permission if an app really needs it.
Write five rules for installing a new app, such as reading what it asks for and installing only from the official store.
What you should see
A table of apps and permissions with the unnecessary ones identified and reduced, a total count before and after, and a set of rules for new apps.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1What is an app permission?
Allowing an app to use a part of the phone or some of your data.
2What is least privilege?
Giving only the access that is actually needed.
3Why might a torch app not need location?
A torch only needs the flash, not your position.
4Where should you install apps from?
Only from the official app store, after reading what they ask for.
Take it further
Repeat after a month and see whether any apps changed their permissions after an update.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
Computer & office
Safe UPI and Digital Payments
Pay and receive money online, and recognise the tricks fraudsters use
Computer & office
Computer Fundamentals Study Book
The complete study notes, practice questions and glossary for Computer Fundamentals