Difference between WPA1-PSK CCMP and WPA2-PSK CCMP

[Paul Lambert]

On Aug 28, 2006, at 9:47 AM, Bryan Kadzban wrote:

> On Tue, Aug 29, 2006 at 01:13:48AM +1000, Nicholas Chan wrote:
>> Hi i noticed in wpa_supplicant, you have a choice between wpa1-psk
>> ccmp and wpa2-psk ccmp.
>>
>> I was wonder what is the difference between them? From the 802.11i
>> standard, it states that wpa1-psk uses TKIP whereas wpa2-psk uses
>> CCMP.
>
> Both WPA1 and WPA2 can use either TKIP or CCMP encryption.  (It is  
> true
> that some APs and some clients restrict the combinations, but there  
> are
> four possible combinations, and AFAIK all of them are Wi-Fi Alliance
> standards.  WPA1 with CCMP may not be, but I believe it is.)
>
> The difference between WPA1 and WPA2 is in the information elements  
> that
> get put into the beacons, association frames, and 4-way handshake
> frames.  The data in these IEs is basically the same, but the  
> identifier
> used is different.  WPA1 uses (one of?) Microsoft's OUI(s) along  
> with an
> ID byte or two that Microsoft guarantees is unique as its IE  
> identifier,
> while WPA2 uses an IE identifier that the IEEE assigned as part of the
> 802.11i standard.
>


The 4-way handshake for WPA2 is also slightly different than WPA in  
the way the 3rd and 4th PDUs are encrypted.


Paul