A method is presented for monitoring a tampering state of closed container wherein a first electrically conductive wire extends across a slot between two portions of the closed container. The method includes applying a voltage across the first electrically conductive wire, sensing a voltage at one end of the first electrically conductive wire, and generating a signal indicating the tampering state of the closed container in response to the sensed voltage. The sensed voltage has a first voltage value if the first electrically conductive wire has been severed by tampering, and this tampered state is then reported using near field communication. The near field communication is blocked if it is sensed that the severed first electrically conductive wire has been repaired.