An electromagnetic radiation (EMR) receiver is located upon a printed circuit board (PCB) glass security layer. EMR flux is transmitted by the glass security layer and received by the EMR receiver. When the PCB is subject to a tamper event the EMR transmitted by glass security layer is increased. A monitoring device that monitors the flux or interference pattern of the EMR received by the EMR receiver detects a change in flux or interference pattern and passes a tamper signal to one or more computer system devices to respond to the tamper event. For example, one or more cryptographic adapter card or computer system functions or secured crypto components may be disabled.