WEP/WPA/WPA2 Key Compromise: Can Transmissions be Read?

TL;DR

Yes, if a third party knows your WEP, WPA, or WPA2 key, they can passively read all unencrypted data transmitted over your Wi-Fi network. The level of effort and time required varies depending on the encryption standard used (WEP is easiest to crack, WPA2 is hardest but still vulnerable). Modern security standards like WPA3 offer better protection.

Understanding the Risks

Your Wi-Fi key protects your network’s data. When someone cracks this key, they gain access to everything sent over the network – websites visited, emails, passwords (if not using HTTPS), and more. Here’s a breakdown by encryption type:

• WEP: Very weak. Can be cracked in minutes with readily available tools.
• WPA: Better than WEP but still vulnerable to dictionary attacks, especially with short or common passwords.
• WPA2: Stronger than WPA, but susceptible to brute-force and dictionary attacks if the password is weak. The KRACK vulnerability also affected some WPA2 implementations (though patches are available).

How a Third Party Reads Transmissions

Once an attacker has your key, they can use tools like Wireshark to capture and decrypt network traffic. Here’s how it generally works:

1. Capture Traffic: The attacker uses a packet sniffer (like Wireshark) in monitor mode on their wireless adapter to intercept all data packets transmitted over your Wi-Fi network.
2. Decrypt Data: Using the cracked WEP/WPA/WPA2 key, the attacker decrypts the captured packets. This reveals the original unencrypted data.
3. Analyze Data: The decrypted data can then be analyzed to steal sensitive information like passwords, browsing history, and personal details.

Checking Your Encryption Type

You need to know what encryption your router is using. Here’s how to check on common operating systems:

• Windows:
  1. Open Command Prompt (search for ‘cmd’).
  2. Type netsh wlan show profiles and press Enter.
  3. Find your Wi-Fi network name in the list.
  4. Type netsh wlan show profile name="Your Network Name" key=clear (replace “Your Network Name” with your actual network name) and press Enter. Look for ‘Authentication’ and ‘Encryption’.
• macOS:
  1. Open Keychain Access (search in Spotlight).
  2. Select Wi-Fi passwords from the left sidebar.
  3. Find your network name, double click it.
  4. Check ‘Show Password’ to see encryption details.

What To Do If You Suspect Your Key Is Compromised

1. Change Your Wi-Fi Password Immediately: Use a strong, unique password (at least 12 characters with a mix of uppercase and lowercase letters, numbers, and symbols).
2. Update Router Firmware: Ensure your router has the latest firmware to patch security vulnerabilities. Check your router manufacturer’s website for updates.
3. Change SSID: Change your network name (SSID) to something less obvious.
4. Enable WPA3 if Possible: If your router and devices support it, switch to WPA3 encryption. It offers significantly improved security.
5. Consider a New Router: Older routers may not support modern security standards or receive firmware updates.

Preventing Key Compromise

• Strong Password: As mentioned, use a strong password.
• Regular Updates: Keep your router’s firmware updated.
• Disable WPS: Wi-Fi Protected Setup (WPS) can be vulnerable to attacks. Disable it in your router settings.
• MAC Address Filtering: While not foolproof, MAC address filtering can add an extra layer of security by only allowing known devices to connect.