A question on WPA

[Jouni Malinen]

On Fri, Oct 01, 2004 at 08:33:23AM -0700, J I wrote:

> I wanted to know if the message 1(from the Authenticator) of the group handshake is tkip encrypted using the PTK installed in fourway handshake.

Yes.

> Further, in case the Authenticator restarts the Four way handshake again after recieving a MIC failure report from the supplicant, are the messages in such a four way handshake are TKIP encrypted using the previously installed PTKs.

Yes, WPA EAPOL-Key packets are encrypted whenever PTK is available. In
this case, the previously installed PTK is used until the end of the new
4-Way Handshake assuming this MIC failure report did not trigger TKIP 
countermeasures (which would remove the old PTK).

-- 
Jouni Malinen                                            PGP id EFC895FA