Network Safety and Wi-Fi Security

Your Connection Is a Vulnerability

You secured your passwords. You can spot phishing. Your devices are locked down. But every time your device connects to a network, data flows between you and the internet. If that connection is compromised, so is your data.

By the end of this lesson, you will know how to stay safe on public Wi-Fi, secure your home network, and decide when a VPN is worth using.

Quick Recall: In the previous lesson, we secured our devices with encryption, automatic updates, and restricted app permissions. Now let us protect the networks those devices connect to.

Public Wi-Fi: The Risks

Coffee shops, airports, hotels, and libraries offer free Wi-Fi. Convenient? Yes. Safe? Not automatically.

What can happen on unsecured public Wi-Fi:

The good news: Most websites now use HTTPS, which encrypts data between your browser and the server. This significantly reduces risk even on public Wi-Fi. But not all traffic is HTTPS, and some apps transmit data insecurely.

Safe Practices on Public Wi-Fi

Always do:

• Verify the network name with staff (avoid fake networks)
• Use HTTPS websites (look for the lock icon)
• Use your mobile data for sensitive tasks when possible
• Turn off auto-connect to known networks
• Disable file sharing and AirDrop in public

Never do:

• Log into banking or financial accounts on public Wi-Fi without a VPN
• Access sensitive work systems without a VPN
• Auto-connect to open networks
• Leave Wi-Fi and Bluetooth enabled when not actively using them

Quick Check: What is an evil twin attack, and how do you protect yourself against it?

When to Use a VPN

A VPN (Virtual Private Network) encrypts all traffic between your device and the VPN server. This means nobody on the local network can see what you are doing.

Use a VPN when:

• On public Wi-Fi and accessing sensitive accounts
• Traveling internationally (especially countries with internet surveillance)
• On any network you do not control and do not trust

A VPN is not necessary when:

• On your secured home network for casual browsing
• Visiting HTTPS-only websites on any network
• You need maximum speed for streaming or gaming

Choosing a VPN provider:

Recommended approach: A reputable paid VPN costs $3-5/month. This is worthwhile if you frequently use public Wi-Fi or travel. For home use only, it is optional.

Securing Your Home Network

Your home Wi-Fi network is the foundation of your digital life. Secure it:

Step 1: Change the router admin password

• Open your router’s admin page (usually 192.168.1.1 or 192.168.0.1)
• Change the admin login from the factory default
• Default credentials are published online; leaving them unchanged means anyone on your network can reconfigure it

Step 2: Set a strong Wi-Fi password

• Use WPA3 encryption if your router supports it (WPA2 at minimum)
• Never use WEP (it is completely broken)
• Choose a strong Wi-Fi password (16+ characters)

Step 3: Update router firmware

• Check your router manufacturer’s website for firmware updates
• Enable automatic updates if available
• Outdated router firmware has known vulnerabilities

Step 4: Set up a guest network

• Create a separate network for visitors and smart home devices
• This isolates guest and IoT traffic from your primary devices
• Guests get internet access without access to your computers and files

Quick Check: Why should you create a separate guest network on your home router?

Smart Home and IoT Security

Smart devices (cameras, speakers, thermostats, doorbells) are convenient but often insecure:

IoT security rules:

• Change default passwords on all smart devices
• Put IoT devices on your guest network (isolates them from your main devices)
• Keep firmware updated on all connected devices
• Research security reputation before buying smart devices
• Disable features you do not use (remote access, voice activation when away)

The concern: Many smart devices have minimal security. A compromised smart camera or speaker can become an entry point to your network. Keeping them on a separate network limits the damage.

Bluetooth Security

Bluetooth is often overlooked:

• Turn off Bluetooth when not actively using it
• Never accept pairing requests from unknown devices
• Remove old paired devices you no longer use
• Be cautious with Bluetooth in public spaces (airports, conferences)

Try It Yourself

Secure your network in the next 20 minutes:

1. Log into your router’s admin page and change the default admin password
2. Check that your Wi-Fi uses WPA2 or WPA3 encryption
3. Set up a guest network for visitors and smart devices
4. Check for router firmware updates and install them
5. Review your phone’s Wi-Fi settings and disable auto-connect to open networks

Key Takeaways

• Public Wi-Fi is risky because other users can intercept unencrypted data; use a VPN for sensitive tasks
• Always verify network names with staff and avoid connecting to suspiciously named networks
• Change your home router’s default admin password immediately because factory credentials are publicly known
• Use WPA3 or WPA2 encryption and set up a guest network to isolate visitors and smart devices
• Turn off Bluetooth and Wi-Fi when not actively using them to reduce your attack surface

Up Next

In Lesson 6: Privacy Online, we will take control of what companies and websites know about you and reduce your digital footprint.