Managing identifier privacy

An apparatus for ensuring that a Subscription Concealed Identifier (SUCI) is calculated in the Universal Subscriber Identity Module (USIM) part of a user equipment (UE) when intended, wherein the UE further comprises a mobile equipment (ME) part that is separate from the USIM part, the apparatus comprising processing circuitry that is configured to:

• initially provisioning the USIM part with a SUCI calculation indicator that indicates that the ME part of the UE should calculate the SUCI for the UE, wherein the USIM part stores the SUCI calculation indicator;
• changing the SUCI calculation indicator stored by the USIM part such that the SUCI calculation indicator indicates that the SUCI should not be calculated in the ME part;
• as a result of the SUCI-calculation indicator being changed from indicating that the SUCI should be calculated in the ME part of the UE to indicating that the SUCI should not be calculated in the ME part of the UE, changing a pre-existing public key of a Home Network (HN).

A Universal Subscriber Identity Module (USIM) of a user equipment (UE) that further comprises a mobile equipment (ME) part that is separate from the USIM, the USIM being configured to:

• store a Subscription Concealed Identifier (SUCI) calculation indicator indicating that the ME part of the UE should not calculate the SUCI for the UE;
• and
• receive from a network node information required for calculation of the SUCI, which information is not known to the ME part of the UE.