Intrusion detection and communication

A device comprising:

• a detector configured to measure a change in value of an operating characteristic of an interconnection circuitry, the operating characteristic of the interconnection circuitry being dependent upon an impedance of the interconnection circuitry;
• a decoder coupled to the detector to receive the measured change in value of the operating characteristic from the detector and configured to decode the measured change in value of the operating characteristic to determine existence of an abnormal condition;
• and
• wherein the decoder is further configured to decode the measured value of the operating characteristic of the interconnection circuit by comparing the measured value of the operating characteristic of the interconnection circuitry with a baseline value of the operating characteristic of the interconnection circuitry.

A device comprising:

• a detector configured to measure a change in value of an impedance of an interconnection circuitry in response to an external input;
• a decoder configured to decode the measured value of the change received from the detector to determine existence of an abnormal condition;
• and
• wherein the change in the value of the impedance is calculated as a difference between a baseline value of impedance of the interconnection circuitry and a test value of impedance of the interconnection circuitry.