Abstract: An apparatus for protecting the confidentiality and security of sensitive data which has been encrypted as it is being processed in data communications systems. The apparatus uses a metallic plate which covers the encryption circuitry and a memory in which the encryption key is stored and includes circuitry which erases the stored encryption key when an attempt is made to remove the protective cover. The metallic plate is formed into top and bottom cover plates for the top side and bottom side respectively of a printed circuit board which are secured together with a screw. An integrated circuit, which is located within the top and bottom cover plates stores the encryption key, an erase circuit and a switch which changes position when the screw is rotated causing a signal to be generated by the erase circuit which erases the encryption key stored in the integrated circuit.