US Patent 11297492 Subscriber identity privacy protection and network key management

Techniques to protect subscriber identity in messages communicated between a user equipment (UE) and a cellular wireless network entity by using multiple ephemeral asymmetric keys are disclosed. The UE determines multiple ephemeral UE public and secret key pairs, while the cellular wireless network entity provides a network public key to the UE. The network public key may be updated over time. Multiple encryption keys based on the multiple ephemeral UE secret keys and the public network key are derived and used to encrypt a subscription permanent identifier (SUPI) to generate multiple subscription concealed identifiers (SUCIs). Each SUCI is used only once for messages communicated to a cellular wireless network and discarded after use. New SUCI are generated when the network public key is updated.