Apparatuses and methods for protecting an initial non-access stratum (NAS) message after a public land mobile network (PLMN) change
AssigneeMediaTek Singapore Pte. Ltd.
InventorsMatti Moisanen, Marko Niemi
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Abstract
A User Equipment (UE) including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception. The controller selects a PLMN via the wireless transceiver, and determines whether a predetermined ciphering algorithm is adopted for a Non-Access Stratum (NAS) security context. In response to selecting the PLMN and the predetermined ciphering algorithm being adopted for the NAS security context, the controller sends an initial NAS message in which Information Elements (IEs) are in cleartext only to the selected PLMN via the wireless transceiver.
Claims18
A User Equipment (UE), comprising:
- a wireless transceiver, configured to perform wireless transmission and reception;
- and
- a controller, configured to select a Public Land Mobile Network (PLMN) via the wireless transceiver, determine whether the UE has a Non-Access Stratum (NAS) security context for which a null ciphering algorithm or a weak confidentiality algorithm is adopted, and in response to selecting the PLMN and the UE having the NAS security context for which the null ciphering algorithm or the weak confidentiality algorithm is adopted, send an initial NAS message in which Information Elements (IEs) are in cleartext only to the selected PLMN via the wireless transceiver.
A method for protecting an initial Non-Access Stratum (NAS) message after a Public Land Mobile Network (PLMN) change, executed by a UE, the method comprising:
- selecting a PLMN;
- determining whether the UE has a Non-Access Stratum (NAS) security context for which a null ciphering algorithm or a weak confidentiality algorithm is adopted;
- and
- in response to selecting the PLMN and the UE having the NAS security context for which the null ciphering algorithm or the weak confidentiality algorithm is adopted, sending an initial NAS message in which Information Elements (IEs) are in cleartext only to the selected PLMN.
Dependencies are inferred from the claim text.