A wireless key is a type of security password exchanged between a router and a wireless client. This key is used to ensure the authenticity of the devices that are trying to connect to a network.

Different standards have been developed by Wi-Fi alliance that uses a wireless key. Some of the common standards include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access) and WPA2.

These standards differ in the number of bits used for the wireless key as well as the algorithm used for encryption of the key.

Keys in different protocols

WEP keys

The first wireless security standard was called Wired Equivalent Privacy (WEP) and was introduced in 1997. WEP used a 40-bit key to authenticate a device. RC4 (Rivest Cipher 4) is used for encryption.

In RC4, the wireless key is manually shared and used for both encoding and decoding of the data.

WPA keys

WPA was introduced in 2003 to counter for the security holes found in WEP. To provide stronger encryption, WPA uses a 128-bit key (as compared to 40 bit in WEP) with TKIP (Temporary Key Integrity Protocol).

Instead of using a fixed key like WEP, TKIP dynamically produces a new key for each data packet being transmitted.

WPA2 keys

WPA2 was developed in 2004, shortly after WPA. WPA2 comes with a stronger security protocol that counters the security flaws found in WPA.

CCMP replaced TKIP in WPA with AES (Advanced Encryption Standard) encryption in WPA2. CCMP stands for Counter Mode Cipher Block Chaining Message Authentication Code Protocol.

In addition to 128-bit keys in WPA, CCMP employs a 48-bit initialisation vector for additional security. The initialisation vector acts as a one time password for each session and helps counter replay attacks.

In a replay attack, transmission of valid data is maliciously repeated or delayed.

What is passphrase?

A passphrase is a sequence of characters used to derive wireless keys. For this purpose, the wireless device converts your passphrase into a hexadecimal key of the required length (for instance, 128 bits).

Passphrases can vary in length and can go up to 63 characters. A minimum of 8 characters is recommended. It is recommended to use a passphrase that is strong and contains at least one lowercase letter, uppercase letter, number, and a special key to ensure proper security.

Doing this makes it very difficult for a hacker to guess or brute force your passphrase and enter your wireless network.

Which wireless key to use?

As discussed above, wireless keys depend on the security protocol being used by your router. Your router may offer you a choice between using WEP, WPA, WPA2-TKIP, and WPA2-AES. WEP is the weakest among all and should be avoided.

On the other hand, WPA2-AES offer maximum security and should be used. Most of the new Wi-Fi equipment supports WPA2-AES.

Once you have selected a security protocol, you will be asked to enter a passphrase. As discussed above, choose a strong passphrase to avoid hackers from stealing your information.

Each wireless device connecting to a wireless local area network requires using the same passphrase. This passphrase or the equivalent key should not be shared with strangers.