Securing Your Devices

Your Devices Are Treasure Chests

Your phone contains your email, banking apps, photos, contacts, messages, and authentication codes. Your laptop holds documents, passwords, and browsing history. If someone gains access to either, they gain access to your life.

By the end of this lesson, you will have locked down the security settings on your most important devices.

Quick Recall: In the previous lesson, we learned to spot phishing attacks and social engineering. Even if you never click a bad link, a physically compromised or unpatched device can expose everything. Let us close those gaps.

The Update Imperative

The single most important device security action: install updates promptly.

When a company discovers a security flaw, they release a patch. When that patch is announced, attackers learn about the flaw too. The time between the patch release and when you install it is when you are most vulnerable.

Enable automatic updates on:

• Operating system (Windows, macOS, iOS, Android)
• Web browser (Chrome, Firefox, Safari)
• Apps (especially email, banking, and messaging apps)

How to enable automatic updates:

• iPhone: Settings > General > Software Update > Automatic Updates > ON
• Android: Settings > System > Software Update > Auto-download > ON
• Windows: Settings > Windows Update > Advanced Options > Automatic
• Mac: System Settings > General > Software Update > Automatic Updates > ON

Smartphone Security Checklist

Your phone is likely the most sensitive device you own. Secure it:

Screen lock:

• Use biometrics (face or fingerprint) for convenience
• Set a 6-digit PIN minimum as backup (not 4-digit)
• Never use pattern locks (they are easy to observe and reproduce)
• Set auto-lock to 1-2 minutes maximum

App permissions:

• Review which apps have access to your camera, microphone, location, and contacts
• Remove permissions that apps do not need for their core function
• A flashlight app does not need your contacts. A calculator does not need your camera.

Find My Device: Enable device tracking so you can locate, lock, or wipe your device if lost:

• iPhone: Settings > [Your Name] > Find My
• Android: Settings > Security > Find My Device

Quick Check: Why should you review app permissions, and what is a red flag that an app is requesting too much access?

Laptop and Desktop Security

Essential settings:

Full disk encryption: Encrypts all data on your drive. If someone steals your laptop, they cannot read your files without your password.

• Mac: System Settings > Privacy & Security > FileVault > Turn On
• Windows: Settings > Privacy & Security > Device Encryption (or enable BitLocker)

Firewall: Blocks unauthorized incoming connections.

• Mac: System Settings > Network > Firewall > ON
• Windows: Settings > Privacy & Security > Windows Security > Firewall

Screen lock:

• Set your computer to lock after 5 minutes of inactivity
• Always lock manually when stepping away: Cmd+Ctrl+Q (Mac), Win+L (Windows)

Browser security:

• Keep your browser updated (most critical software on your computer)
• Install a reputable ad blocker (uBlock Origin): blocks malvertising
• Clear cookies periodically or use a privacy-focused browser for sensitive tasks
• Avoid browser extensions you do not trust; each one can see everything you do

The App Security Mindset

Not all software is trustworthy. Follow these rules:

Only install from official sources:

• App Store (Apple), Google Play Store (Android)
• Official websites for desktop software
• Never install software from email attachments or random websites

Before installing any app, check:

• Developer reputation (known company or established developer?)
• Reviews (look for complaints about privacy or security)
• Permissions requested (proportional to the app’s function?)
• Last updated (apps not updated in years may have unpatched vulnerabilities)

Quick Check: What does full disk encryption protect against, and why is it important for laptop security?

Physical Device Security

Digital security means nothing if someone physically accesses your device:

At home:

• Do not leave devices unattended when guests are present
• Set up guest Wi-Fi networks for visitors (keeps them off your main network)

In public:

• Never leave devices unattended, even briefly
• Use a privacy screen protector (prevents shoulder surfing)
• Be aware of who can see your screen in coffee shops and airports

When traveling:

• Enable device tracking before you travel
• Back up your device before the trip
• Use a VPN on hotel and airport Wi-Fi (more on this in the next lesson)
• Consider using a dedicated travel device for high-risk destinations

Device Disposal

When you sell, donate, or recycle a device:

1. Back up any data you want to keep
2. Sign out of all accounts (email, iCloud, Google, banking)
3. Remove all linked payment methods
4. Perform a factory reset
5. Remove SIM card and microSD cards

Factory reset is not optional. Simply deleting files leaves recoverable data on the device.

Try It Yourself

Secure your devices in the next 15 minutes:

1. Enable automatic updates on your phone and computer
2. Review app permissions on your phone (revoke unnecessary access)
3. Enable full disk encryption if not already active
4. Turn on your device firewall
5. Enable Find My Device on your phone
6. Set auto-lock to 2 minutes or less on all devices

Key Takeaways

• Install software updates promptly; they fix known vulnerabilities that attackers actively exploit
• Review and restrict app permissions to only what each app genuinely needs for its core function
• Enable full disk encryption on laptops so stolen devices cannot be read without your password
• Only install software from official sources and verify developer reputation before installing
• Always factory reset devices before selling, donating, or recycling them

Up Next

In Lesson 5: Network Safety and Wi-Fi Security, we will protect the connections your devices use to communicate with the internet.