Security verification when resuming an RRC connection

1 . A method, in a wireless device operating in a wireless network, for providing security of messages, the method comprising:

generating one or more security keys for encryption of signaling and/or data, using one or more security parameters received by the wireless device while in a Radio Resource Control (RRC) inactive state;

sending, while in the RRC inactive state, a message requesting resumption of an RRC connected state;

starting a timer according to a predetermined value, upon sending the message; and

while said timer is running, attempting decryption for all packets received from the wireless network, using the generated one or more security keys.

2 . The method of claim 1 , wherein attempting decryption comprises an RRC layer requesting decryption from a Packet Data Convergence Protocol (PDCP) layer.

3 . The method of claim 1 , wherein the method further comprises:

while said timer is running, determining that decryption has failed for a packet; and

discarding the packet for which decryption has failed.

4 . The method of claim 3 , wherein said determining is performed in a first protocol layer and the method further comprises the first protocol layer notifying a higher protocol layer of the failure.

5 . The method of claim 1 , wherein the method further comprises:

while said timer is running, successfully decrypting a message indicating a resumption of the RRC connected state; and

responsive to said successfully decrypting a message, stopping the timer and entering the RRC connected state.

6 . The method of claim 5 , wherein the method further comprises, subsequently to entering the RRC connected state:

determining that a packet received while in the RRC connected state has failed integrity checking; and

responsive to the failed integrity checking, initiating a re-establishment of the RRC connected state.

7 . The method of claim 1 , wherein the method further comprises:

determining that the timer has expired and, in response to the timer expiring, discarding stored information regarding the RRC connection.

8 . The method of claim 7 , wherein said determining that the timer has expired and said discarding the stored information is performed in a first protocol layer, and the method further comprises the first protocol layer notifying a higher protocol layer that resumption of the RRC connection failed.

9 . The method of claim 1 , wherein the method further comprises:

while said timer is running, determining that decryption has failed for a packet; and

responsive to determining that decryption has failed for the packet, discarding stored information regarding the RRC connection and notifying a higher protocol layer that resumption of the RRC connection failed.

10 . The method of claim 1 , wherein the method further comprises:

receiving a message indicating that resumption of the RRC connected state is rejected, wherein the message indicates that resumption of the RRC connected state is not encrypted; and

responsive to receiving said message, discarding stored information regarding the RRC connection.

11 . A wireless device configured for operating in a wireless network and for providing security of messages, the wireless device comprising:

transceiver circuitry; and

processing circuitry operatively associated with the transceiver circuitry and configured to:

generate one or more security keys for encryption of signaling and/or data, using one or more security parameters received by the wireless device while in a Radio Resource Control (RRC) inactive state;

send, while in the RRC inactive state, a message requesting resumption of an RRC connected state;

start a timer according to a predetermined value, upon sending the message; and

while said timer is running, attempt decryption for all packets received from the wireless network, using the one or more generated security keys.

12 . The wireless device of claim 11 , wherein the processing circuitry is configured to attempt decryption by having a RRC layer request decryption from a Packet Data Convergence Protocol (PDCP) layer.

13 . The wireless device of claim 11 , wherein the processing circuitry is configured to:

while said timer is running, determine that decryption has failed for a packet; and

discard the packet for which decryption or integrity checking has failed.

14 . The wireless device of claim 11 , wherein the processing circuitry is configured to:

while said timer is running, successfully decrypt a message indicating a resumption of the RRC connected state; and

responsive to said successfully decrypting a message, stop the timer and entering the RRC connected state.

15 . The wireless device of claim 14 , wherein the processing circuitry is configured to, subsequently to entering the RRC connected state:

determine that a packet received while in the RRC connected state has failed integrity checking; and

responsive to the failed integrity checking, initiate a re-establishment of the RRC connected state.

16 . The wireless device of claim 11 , wherein the processing circuitry is configured to:

determine that the timer has expired and, in response to the timer expiring, discard stored information regarding the RRC connection.

17 . The wireless device of claim 16 , wherein the processing circuitry is configured to determine that the timer has expired and discard the stored information in a first protocol layer, the first protocol layer notifying a higher protocol layer that resumption of the RRC connection failed.

18 . The wireless device of claim 11 , wherein the processing circuitry is configured to:

while said timer is running, determine that decryption has failed for a packet; and

responsive to determining that decryption has failed for the packet, discard stored information regarding the RRC connection and notifying a higher protocol layer that resumption of the RRC connection failed.

19 . The wireless device of claim 11 , wherein the processing circuitry is configured to:

receive a message indicating that resumption of the RRC connected state is rejected, wherein the message indicates that resumption of the RRC connected state is not encrypted; and

responsive to receiving said message, discard stored information regarding the RRC connection.