Ready for Transfer

NSA’s Detecting SIM Card Removal and Reinsertion

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Laboratory: National Security Agency (NSA)

Technology: Detecting SIM card removal and reinsertion

Opportunity: The SIM card detection system has completed all of its developmental stages and is available to license through the NSA. 

Details: This technology detects the removal and reinsertion of a Subscriber Identity Module (SIM) card. Existing technology can determine when a SIM card not associated with a specific device has been inserted in that device, i.e., when a thief replaces the SIM card in a phone. This technology goes a step further in detecting reinsertion of the same card. This detection helps prevent unauthorized use of electronic devices. The invention monitors any removal and reinsertion, and displays the results on a graphical user interface (GUI). The system can correlate SIM card removal with other events associated with the device, activating alerts of unauthorized activity.

Benefits: Among the many security benefits of this technology, the detection system can correlate between the time of SIM card removal/reinsertion and other events. It also provides greater context on unauthorized activity, and is able to check for stolen data or malicious software to prevent the attack from continuing. The system also allows the logging of events and event history, and provides continuous communications to the device to detect failure of communication capabilities.

Potential Applications: Complementing the system’s features are applications in the following areas:

  • Medical/pharmaceuticals
  • Anti-tamper applications
  • Notification of equipment failure (automotive, aerospace, manufacturing)
  • Anti-counterfeiting applications.

Contact: For more information on the SIM card detection system, contact the NSA Office of Research and Technology Applications at, or visit