Optical chassis intrusion detection with power on or off

A method of detecting intrusion into a chassis, comprising:

• sensing a presence of ambient electromagnetic radiation an opened chassis from outside of the chassis due to an opening of said chassis by an electromagnetic radiation detector;
• generating a detection signal with said electromagnetic radiation detector;
• and
• latching said detection signal at an output of a latching mechanism coupled to said electromagnetic radiation detector.

An optical intrusion detection system for a computer comprising:

• a computer including a chassis enclosing a motherboard and an optical intrusion detection device, the optical intrusion detection device includes
• an electromagnetic radiation detector having an output, where said electromagnetic radiation detector is capable of sensing and generating a detection signal in response to an opening of said chassis and a presence of ambient electromagnetic radiation within said chassis from outside of the chassis due to the opening of said chassis;
• and
• a latching mechanism having an input coupled to the output of said electromagnetic radiation detector and an output, where said latching mechanism is capable of latching said detection signal at its output, said detection signal is present at the output of said latching mechanism after the presence of electromagnetic radiation at said electromagnetic radiation detector is removed.