Complete WiFi Security Guide

1. WiFi Security Fundamentals

WiFi networks broadcast data over radio waves, making them inherently more vulnerable than wired connections. Anyone within range can potentially intercept wireless traffic. WiFi security protocols encrypt this traffic and authenticate devices to prevent unauthorized access.

The evolution of WiFi security has been driven by the discovery of vulnerabilities in previous protocols. Understanding this evolution helps you make informed decisions about securing your networks.

2. Security Protocols (WEP to WPA3)

2.1 WPA3 Improvements

• SAE (Dragonfly): Replaces PSK handshake, resistant to offline dictionary attacks
• Forward Secrecy: Past traffic can't be decrypted even if password is later compromised
• Protected Management Frames: Prevents deauthentication attacks
• 192-bit Security Suite: For enterprise/government networks

3. Common WiFi Attacks

3.1 Evil Twin Attack

Attackers create a fake access point with the same SSID as a legitimate network. Victims connect to the rogue AP, allowing the attacker to intercept traffic or present fake login pages.

3.2 Deauthentication Attack

Attackers send forged deauth frames to disconnect clients. Used to force reconnection for handshake capture or to push victims toward evil twin networks.

3.3 WPA2 Handshake Capture

# Capture handshake with aircrack-ng suite
airodump-ng wlan0mon --bssid AA:BB:CC:DD:EE:FF -c 6 -w capture

# Deauth to force reconnection
aireplay-ng -0 5 -a AA:BB:CC:DD:EE:FF wlan0mon

# Crack with wordlist
aircrack-ng -w rockyou.txt capture-01.cap

3.4 KRACK (Key Reinstallation Attack)

Vulnerability in WPA2 4-way handshake allowing key reinstallation. Fixed in most devices via patches. WPA3 eliminates this vulnerability.

4. Home Network Security

4.1 Router Configuration

• Change default admin password: Factory passwords are publicly known
• Use WPA3 or WPA2-AES: Never WEP or WPA2-TKIP
• Strong WiFi password: 15+ characters, random
• Disable WPS: Vulnerable to brute force (Reaver attack)
• Update firmware: Regularly check for security patches
• Disable remote management: Unless specifically needed

4.2 Network Segmentation

# Recommended network segments:
1. Primary Network - Trusted devices (computers, phones)
2. IoT Network - Smart home devices (separate SSID/VLAN)
3. Guest Network - Visitors (isolated from main network)

# Many routers support guest network isolation
# Enable this to prevent guest access to main network devices

4.3 Hidden SSID

Hiding your SSID provides minimal security benefit. Your network still broadcasts probe responses, and hidden networks actually stand out in scans. It causes usability issues and is not recommended as a security measure.

5. Enterprise WiFi Security

5.1 WPA2/WPA3-Enterprise

Uses 802.1X authentication with a RADIUS server instead of a shared password. Each user has unique credentials, enabling individual access revocation and audit trails.

# RADIUS authentication flow:
1. Client connects to AP
2. AP forwards auth request to RADIUS server
3. RADIUS validates credentials (LDAP, AD, etc.)
4. If valid, unique session keys are generated
5. User is authorized with appropriate VLAN/policies

5.2 EAP Methods

5.3 Rogue AP Detection

Enterprise wireless intrusion prevention systems (WIPS) monitor the airspace for unauthorized access points and can alert or take automated action.

6. Public WiFi Safety

• Use VPN: Encrypts all traffic regardless of network security
• Verify network name: Ask staff for the correct SSID
• Avoid sensitive activities: Banking, shopping on public WiFi
• Disable auto-connect: Prevent automatic connection to open networks
• Use HTTPS: Ensure websites use HTTPS (browser padlock)
• Forget network after use: Remove from saved networks

7. WiFi Security Tools

8. Frequently Asked Questions

Conclusion

WiFi security requires attention to protocol selection, password strength, and network architecture. Use WPA3 where possible, implement strong passwords, keep firmware updated, and segment your network. For enterprises, WPA2/3-Enterprise with RADIUS provides the accountability and security needed for business environments.

Continue Learning:
Network Security VPN Guide