Mobile network operator (MNO)-specific 5G functionality information may be distributed by an MNO to a user device. A request from a mobile network operator (MNO) to provide MNO-specific 5G functionality information of the MNO to a user device may be received. In turn, a messaging service may be directed to deliver the MNO-specific 5G functionality information to the user device for storage in an MNO-specific memory area allocated for the MNO in a trusted environment of the user device. The MNO-specific 5G functionality information may instruct the user device to use an encryption key stored in the trusted environment or an Embedded Subscriber Identity Module (eSIM) of the user device to encrypt or decrypt subscriber identifier information of the user device. The encrypted subscriber identifier information is used for 5G communications exchanged between the user device and a core network of a wireless carrier network operated by the MNO.