Take the 2-minute tour ×
Information Security Stack Exchange is a question and answer site for Information security professionals. It's 100% free, no registration required.

I am researching about the weaknesses of WPA with TKIP. I have an idea that the AES-CCMP mode is better than TKIP, but what are the weakest points of TKIP? Also, I am wondering about the disadvantages of WPA TKIP. What are the disadvantages over WPA-AES?

share|improve this question
    
WPA-TKIP is very weak to DOS attacks. –  Delininbiri Jun 15 at 16:40

1 Answer 1

Here's a relevant excerpt from a blogpost I did on here a few months ago:

WPA generally uses Temporal Key Integrity Protocol (TKIP). TKIP was designed by the IEEE 802.11i task group and the Wi-Fi Alliance as a solution to replace WEP without requiring the replacement of legacy hardware. This was necessary because the breaking of WEP had left WiFi networks without viable link-layer security, and a solution was required for already deployed hardware. TKIP is not an encryption algorithm, but it's used to make sure that every data packet is sent with a unique encryption key.

An excerpt from the aircrack-ng paper, Practical attacks against WEP and WPA:

TKIP implements a more sophisticated key mixing function for mixing a session key with an initialization vector for each packet. This prevents all currently known related key attacks because every byte of the per packet key depends on every byte of the session key and the initialization vector. Additionally, a 64 bit Message Integrity Check (MIC) named MICHAEL is included in every packet to prevent attacks on the weak CRC32 integrity protection mechanism known from WEP. To prevent simple replay attacks, a sequence counter (TSC) is used which allows packets only to arrive in order at the receiver.

There are two attacks known against TKIP:

  • Beck-Tews attack
  • Ohigashi-Morii attack (which is an improvement on the Beck-Tews attack)

Both of these attacks only could decrypt small portions of data, compromising confidentiality. What they can't give you is access to the network. To give you an idea of how much data can be recovered, a single ARP frame would take around 14-17 minutes to get the plain text. Getting useful information with this type of attack is very improbable (but not impossible) considering the rate of recovery.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.