126.96.36.199 Facility shields. When a facility shield is required, it should be
designed and installed using EMP guidelines, as well as those for containing
compromising emanations. Consult the Defense Nuclear Agency for EMP
188.8.131.52 Cable shields. Al) cables in a facility (signal and power, RED and
BLACK) should have at least an overall nonferrous circumferential shield. In
addition, ferrous shielding should be used for high-level signals, or where
indicated by TEMPEST tests. All cable shields shall be closed at both ends
by bonding the shield circumference to the equipment enclosure (case, rack,
etc.). A circumferential bond through a connector is achieved by using a
connector which has a conductive shell that makes 360-degree contact with
both the shield and with the mating connector. The requirement for an
overall shield may be satisfied by complete enclosure within conduits, ducts,
and equipment cabinets.
4.7 General guidance on physical security. The purpose of physical security
Is to make access to a facility so difficult that a potential intruder will
be (a) thwarted in attempting penetration, or (b) apprehended should the
attempted penetration be successful.
4.7.1 Scope. It is not economically possible, nor theoretically necessary,
for every facility that processes classified information to achieve the same
degree of physical protection. How much physical protection is prudent in
any particular case depends on factors such as type of facility,
classification level of information stored/processed, threat of hostile
intelligence forces, geopolitical climate of the area, location of the
facility, and existing physical security measures.
4.7.2 Objectives of physical security. Physical security programs are
designed to prevent unauthorized access to classified facilities, equipment,
material, and documents, and to protect against espionage, sabotage, and
theft. Physical security provides protection against human intelligence
and similar equipment, physical security also provides protection against
some aspects of signals intelligence (SIGINT). (See JCS Pub 1.)
4.7.3 Facility security. Security of a facility begins by establishing a
CAA within the facility in order to control access to classified information.
Figures 14 and 15 are representations of this concept.
4.7.4 Audio security. Audio security is implemented to suppress the
possibility of classified conversations being intercepted by clandestine
means. Sound cover systems, special treatment of administrative telephones,
and acoustic suppression techniques within buildings are the principle
methods of audio security.
4.7.5 Intrusion detection. Intrusion detection systems (IDS) use sensors to
monitor specific conditions within a CS and to alert security personnel when
an undesirable condition exists. Guidance for such systems is defined by
service/agency directives. The design may, in some cases, be incorporated
into the facility cable design and may require protection as defined in this
4.7.6 Technical security. Ducting, wire ways, or race ways in a facility
may require protection to prevent the introduction of clandestine devices.
If ducts that contain transmission media, transporting classified plain text
information, traverse nonsecure areas, then specific protection is mandated,
such as a PDS.