Patent ID: 8630416
Filing Date: 2014-01-14
Classification: H04L,H04W

Abstract:
1. A method performed by an authenticator for toggling between keys during an established secure communication session with a supplicant, the established secure communication session using a current pair-wise key for unicast communications, the method comprising: installing a new pair-wise key for reception prior to receipt of a rekeying confirmation message; continuing to use the current pair-wise key for transmission and delaying use of the new pair-wise key for transmission until after receipt of the rekeying confirmation message, wherein after installing the new pair-wise key for reception and prior to receipt of the rekeying confirmation message, the method further comprises: receiving a unicast packet that includes a key ID field, the key ID field including a key ID portion and an Extended Key ID bit, the key ID portion identifying one of a plurality of keys, the Extended Key ID bit indicating whether to toggle between the current pair-wise key and the new pair-wise key; reading the Extended Key ID bit in the key ID field of the received unicast packet to determine whether to decrypt the received unicast packet using the installed current pair-wise key or the installed new pair-wise key; continuing to use the current pair-wise key for transmission; the authenticator installing the new pair-wise key for use in decrypting received packets after receipt of a second message of the four-way handshake and prior to transmission of a third message of the four-way handshake; and the authenticator delaying use of the new pair-wise key for use in encrypting packets for transmission until after receipt of the fourth message and wherein the installing is performed by processing circuitry of the authenticator and the current and new pair-wise keys are stored in unicast key ID space of a memory; and further wherein the rekeying confirmation message is a fourth message of a four-way handshake for rekeying; and further wherein the supplicant is to install the new pair-wise key for reception prior to transmission of the rekeying confirmation message and is to delay using the new pair-wise key for transmission until after the transmission of the rekeying confirmation message; and further wherein the supplicant is to delay using the new pair-wise key for transmission until immediately after sending the rekeying confirmation message or a predetermined period of time after sending the rekeying confirmation message; and further wherein after installing the new pair-wise key for reception prior to receipt of the rekeying confirmation message, the method includes selecting either the new pair-wise key or the current pair-wise key for decrypting received unicast packets based on a key identifier carried in the received unicast packets; and further wherein the supplicant installs the new pair-wise key for use in decrypting received messages after receipt of the third message and prior to transmission of the fourth message, and wherein the supplicant delays installing the new pair-wise key for use in encrypting packets for transmission until either immediately after transmission of the fourth message or a predetermined period of time after transmission of the fourth message.