The red/black principle, also known as red/black architecture or red/black engineering, represents the meticulous separation and partitioning in cryptographic systems of signals that contain sensitive or classified plain-text information (red signals) from those that carry encrypted information, or cipher-text (black signals).
All TEMPEST standards require a strict "RED/BLACK separation or the installation of shielding agents with satisfactory SE, between all circuits and equipment which transmit classified and non-classified data.
The manufacture of TEMPEST-approved equipment must be done under careful quality control to ensure that additional units are built exactly the same as the units that were tested. Changing even a single wire can invalidate the tests.
Military applications pose a major challenge for the integration of touchscreens. A touchscreen for military applications must withstand extreme conditions, function highly reliably and comply with all EMC specifications.