Handling of multiple authentication procedures in 5g

A non-transitory computer readable medium comprising instructions that, when executed by a processor in a host computer of a communication system, cause the host computer to perform operations comprising:

• providing user data;
• and
• forwarding the user data to a cellular network, via a communication interface, for transmission to a user equipment (UE), wherein the cellular network comprises an Authentication Server Function, AUSF, of a home public land mobile network, PLMN, configured to communicate through an interface with electronic devices, the AUSF configured to perform operations comprising:
• receiving a first authentication request from a first PLMN that is authenticating an electronic device;
• obtaining a first security key used for integrity protection of messages delivered from the home PLMN to the electronic device, wherein the first security key is obtained in response to successful authentication based on the first authentication request;
• receiving a second authentication request from a second PLMN that is authenticating the electronic device;
• obtaining a second security key used for integrity protection of the messages delivered from the home PLMN to the electronic device, wherein the second security key is obtained in response to successful authentication based on the second authentication request;
• receiving a message protection request;
• determining which of the first security key and the second security key is a latest security key;
• and
• using the latest security key to protect a message associated with the message protection request.

A method performed by a host computer in a communication system, comprising:

• providing user data;
• and
• forwarding the user data to a cellular network, via a communication interface, for transmission to a user equipment (UE), wherein the cellular network comprises an Authentication Server Function, AUSF, of a home public land mobile network, PLMN, configured to communicate through an interface with electronic devices, the AUSF configured to perform operations comprising:
• receiving a first authentication request from a first PLMN that is authenticating an electronic device;
• obtaining a first security key used for integrity protection of messages delivered from the home PLMN to the electronic device, wherein the first security key is obtained in response to successful authentication based on the first authentication request;
• receiving a second authentication request from a second PLMN that is authenticating the electronic device;
• obtaining a second security key used for integrity protection of the messages delivered from the home PLMN to the electronic device, wherein the second security key is obtained in response to successful authentication based on the second authentication request;
• receiving a message protection request;
• determining which of the first security key and the second security key is a latest security key;
• and
• using the latest security key to protect a message associated with the message protection request.