Subscriber Identity Module (SIM/USIM) smart cards contain tamper-resistant cryptographic microcontrollers running secure Java Card applets.

1. SIM Card Technologies

  • Over-The-Air (OTA) Management: Operators use encrypted Point-to-Point SMS (SMS-PP) commands to update Preferred Roaming Lists (PRL) and authentication keys remotely.
  • eSIM Remote SIM Provisioning (RSP): GSMA SGP.22 architecture enables secure digital profile downloads to embedded eUICC chips via TLS mutual authentication.
  • SIM-Swap Fraud Countermeasures: Mobile carriers track IMSI-to-ICCID binding timestamps to alert financial institutions when a subscriber's physical SIM has been recently re-issued.