Like every other website on the planet, SmallNetBuilder uses cookies. Our cookies track login status, but we only allow admins to log in anyway, so those don't apply to you. Any other cookies you pick up during your visit come from advertisers, which we don't control.
If you continue to use the site, you agree to tolerate our use of cookies. Thank you!

Router Charts

Click for Router Charts

Router Ranker

Click for Router Ranker

NAS Charts

Click for NAS Charts

NAS Ranker

Click for NAS Ranker

More Tools

Click for More Tools

Wireless How To

Introduction

There is a new version of this article here.

Previously, we showed you how to secure your wireless with industrial strength RADIUS authentication via WPA-Enterprise. It turns out that there's a little back-story there. So, in traditional Tarentino fashion, now that we've already seen the ending, let's back up to the beginning: cracking WPA-PSK.

Wi-Fi Protected Access (WPA) was created to solve the gaping security flaws that plagued WEP. Perhaps the most predominant flaw in WEP is that the key is not hashed, but concatenated to the IV, allowing completely passive compromise of the network. With WEP, you can literally sit in your car listening for packets on a network. Once you have captured enough of them, you can extract the key and connect to the network.

WPA solves this problem by rotating the key on a per-packet basis, which renders the above method useless. However, nothing is perfectly secure, and WPA-PSK is particularly vulnerable during client association, during which the hashed network key is exchanged and validated in a "four-way handshake".

The Wi-Fi Alliance, creators of WPA, were aware of this vulnerability and took precautions accordingly. Instead of concatenating the key in the IV (the weakness of WEP), WPA hashes they key using the wireless access point's SSID as a salt. The benefits of this are two-fold.

First, this prevents the statistical key grabbing techniques that broke WEP by transmitting the key as a hash (cyphertext). It also makes hash precomputation via a technique similar to Rainbow Tables more difficult because the SSID is used as a salt for the hash. WPA-PSK even imposes a eight character minimum on PSK passphrases, making bruteforce attacks less feasible.

So, like virtually all security modalities, the weakness comes down to the passphrase. WPA-PSK is particularly susceptible to dictionary attacks against weak passphrases. In this How To, we'll show you how to crack weak WPA-PSK implementations and give you some tips for setting up a secure WPA-PSK AP for your SOHO.

NOTE!Warnings:
  • Accessing or attempting to access a network other than your own (or have permissions to use) is illegal.
  • SmallNetBuilder, Pudai LLC, and I are not responsible in any way for damages resulting from the use or misuse of information in this article.

NOTE!Note: The techniques described in this article can be used on networks secured by WPA-PSK or WPA2-PSK. References to "WPA" may be read "WPA/WPA2".

More Wireless

Wi-Fi System Tools
Check out our Wi-Fi System Charts, Ranker and Finder!

Support Us!

If you like what we do and want to thank us, just buy something on Amazon. We'll get a small commission on anything you buy. Thanks!

Over In The Forums

Hi all,don´t know if this is normal or not but everytime I change the channel for 5Ghz Wifi to 100 or above it is changing the channel to 48 or 64. I ...
Hello,Anyone seen this? AC86U router, AC68U Aimesh Node, both are 384.17 (upgraded to 384.17, restore default manufacturer, even hard reset as well).....
I'm thinking if I should get a pair Asus Zenwifi CT8 at discounted rates from my ISP.I intend to run RT-AC68U (main router) with x2 CT8 (in Aimesh nod...
Hi, I have two routers: RT-AC3100 as principal router connected to my ISP Cablemodem, then an RT-AC66_B1 configured as Access Point to extend my wire ...
I found my wireless connection really slow today. My Wi-Fi speed is fluctuating like crazy and speed is really slow. I called my broadband provider, P...

Don't Miss These

  • 1
  • 2
  • 3