Wi-Fi Protected Access Pre-Shared Key (WPA-PSK)

Last Updated: June 23, 2020

Definition - What does Wi-Fi Protected Access Pre-Shared Key (WPA-PSK) mean?

Wi-Fi Protected Access Pre-Shared Key or WPA-PSK is a system of encryption used to authenticate users on wireless local area networks. It's typically utilized by telecom companies for end user access in home local area networks.

WPA-PSK may also be called WPA2-PSK or WPA Personal.

Techopedia explains Wi-Fi Protected Access Pre-Shared Key (WPA-PSK)

With WPA-PSK protocol, data transmission is encrypted and controlled using an end user’s generated password. With a TKIP protocol, WPA-PSK uses 128-bit encryption. WPA-PSK can be used with the AES standard, which is a common standard in cybersecurity analysis.

Unlike commercial WPA systems, the WPA-PSK method doesn't require a central server or various kinds of user-driven inputs.

WEP and WPA

It's important to note that WPA-PSK is one of multiple alternatives for this type of wireless LAN authentication and validation.

Another one is called Wired Equivalent Protection (WEP).

Interestingly, both of these protocols use a pre-shared key, but the encryption on WEP is considered weaker than the encryption on WPA systems. As a result, some telecom services have moved to using WPA instead of WEP protocol for encryption and authentication.

WPA and the Pre-Shared Key

One of the fundamental aspects of WPA-PSK security is the use of a pre-shared key.

The concept of a pre-shared key goes all the way back to primitive non-digital cryptography in prior centuries. The idea is that users utilized an initial secure channel to deliver a key, and then subsequently at a future time, sent secondary transmissions where encryption depended on that initial key.

One can think of some of the simple book ciphers of the early to mid-millennium where recipients used the pre-shared key to decode messages sent encrypted in the printed pages of a book. The key was often a book in which both the sender and receiver could measure equidistant letter sequence markings. The key could be delivered in person.

After that, the sender could send a set of numbers corresponding to an equidistant sequence matching the letters in the book. Without the underlying book, the pre-shared key, the set of numbers would defy analysis or code-breaking. The code was not a cipher, then, but a reference to the pre-shared key itself.

In the current context, the pre-shared key is a digital asset that unlocks the encrypted messaging sent over the network. As such, it can be useful in helping to resist brute force attacks where hackers are trying to break the encryption after successfully intercepting transmitted data packets. Again, the pre-shared key makes the encrypted data less dependent on hackable ciphers.

Although a pre-shared key and other aspects of WPA-PSK may be useful in this type of authentication system, the standard for authentication is moving from a simple password system to multi-factor authentication (MFA).

One of the most common methods is to use a smartphone as a secondary device authentication factor. Here, where it may be possible to hack a password through a brute-force attack, the MFA makes it harder to break into a user account, because unless the hacker somehow has the verification key sent to the mobile device, attempts at unauthorized access won’t work.

The first WPA standard became available in 2003. A subsequent standard, WPA2, was introduced the next year. A new WPA3 standard became available in 2018.

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