Mobile station security mode method
View Patent ↗A security mode method ( 200 ) receives ( 210 ) a layer 3 message in a first domain from a network, determines ( 220 ) if the layer 3 message has integrity protection information, ascertains ( 240 ) if a security mode has been initiated in the first domain, and forwards ( 260 ) the layer 3 message to an upper layer, if the layer 3 message lacks integrity protection information and a security mode has not been initiated in the first domain even if security mode has been initiated in a second domain. This method allows a mobile station to process a non-integrity-protected layer 3 message from one domain even if integrity protection has been initiated in another domain. When packet-switched and circuit-switched connections are being concurrently set up, a non-integrity-protected message in one domain may arrive at a mobile station after an integrity protection initiation message in another domain.
1. A security mode method comprising:
receiving, at a mobile station, a layer 3 message in a first domain from a network;
determining, by the mobile station, if the layer 3 message has integrity protection information;
ascertaining, by the mobile station, if a security mode has been initiated in the first domain;
detecting, by the mobile station, if a security mode has been initiated in a second domain; and
forwarding the layer 3 message to an upper layer of the mobile station, if the layer 3 message lacks integrity protection information and a security mode has not been initiated in the first domain and has been initiated in the second domain.
2. A security mode method according to claim 1 further comprising:
performing, at the mobile station, integrity protection on the layer 3 message, if the layer 3 message has integrity protection information.
3. A security mode method according to claim 1 further comprising:
discarding the layer 3 message, by the mobile station, if the layer 3 message lacks integrity protection information and a security mode has been initiated in the first domain.
4. A security mode method according to claim 1 wherein the first domain is a circuit-switched domain and the second domain is packet-switched domain.
5. A security mode method according to claim 1 wherein the first domain is a packet-switched domain and the second domain is circuit-switched domain.
6. A security mode method according to claim 1 wherein determining, by the mobile station, if the layer 3 message has integrity protection information comprises:
checking for an information element “Integrity check info.”
7. A security mode method according to claim 1 wherein ascertaining, by the mobile station, if a security mode has been initiated in the first domain comprises:
checking for receipt of an integrity protection initiation command message in the first domain.
8. A security mode method according to claim 1 wherein detecting, by the mobile station, if a security mode has been initiated in a second domain comprises:
checking for receipt of an integrity protection initiation command message in the second domain.
9. A security mode method according to claim 1 wherein ascertaining, by the mobile station, if a security mode has been initiated in the first domain comprises:
checking a variable for a value that indicates that integrity protection has started in the first domain.
10. A security mode method according to claim 1 wherein detecting, by the mobile station, if a security mode has been initiated in a second domain comprises:
checking a variable for a value that indicates that integrity protection has started in the second domain.
11. A security mode method according to claim 1 wherein the upper layer is a mobility management layer for the first domain.
12. A security mode method comprising:
establishing a radio resource control connection between a mobile station and a network;
receiving, at the mobile station, a security mode initiation message for a first domain from the network;
completing, by the mobile station, security mode initiation;
receiving, at the mobile station, a layer 3 message for a second domain from the network; and
forwarding the layer 3 message to a mobility management layer of the mobile station for the second domain.
13. A security mode method according to claim 12 wherein the first domain is circuit-switched and the second domain is packet-switched.
14. A security mode method according to claim 12 wherein the first domain is packet-switched and the second domain is circuit-switched.
15. A security mode method according to claim 12 wherein the layer 3 message is an authentication request.
16. A security mode method according to claim 15 wherein the layer 3 message is an authentication request for a circuit-switched domain.
17. A security mode method according to claim 15 wherein the authentication request is an authentication & ciphering request for a packet-switched domain.
18. A security mode method according to claim 12 further comprising:
receiving, at the mobile station, a layer 3 message for the first domain from the network, before receiving a security mode initiation message for a first domain from the network.
19. A security mode method according to claim 12 further comprising:
receiving, at the mobile station, a security mode initiation message for the second domain from the network.