C. Although an organization would not want to report a large number of incidents unless

Two or more of these types of intrusion and alarm systems can be incorporated in a single solution. However, there are two aspects of any intrusion detection and alarm system that can cause it to fail: how it gets its power and how it communicates. If the system loses power, it will not function. Thus, a reliable detection and alarm system has a battery backup with enough stored power for 24 hours of operation. If the communication lines are cut, the alarm may not function and security personnel and emergency services will not be notified. Thus, a reliable detection and alarm system has a heartbeat sensor for line supervision. A heartbeat sensor is a mechanism by which the communication pathway is either constantly or periodically checked with a test signal. If the receiving station ever detects a failed heartbeat signal, the alarm is trig- gered automatically. Both of these measures are designed to prevent an intruder from circum- venting the detection and alarm system. Emanation Security Many electrical devices emanate electrical signals or radiation that can be intercepted by unau- thorized individuals. These signals may contain confidential, sensitive, or private data. Obvious examples of emanation devices are wireless networking equipment and mobile phones, but there are many other devices that that are vulnerable to interception. Some possible examples could be monitors, modems, and internal and external media drives hard drives, floppy drives, CDs, etc.. With the right equipment, unauthorized users could intercept the electromagnetic or radio frequency signals collectively known as emanations and extract confidential data. TEMPEST Clearly, if a device is sending out a signal that can be intercepted by someone outside of your orga- nization, a security precaution is needed. The types of countermeasures and safeguards used to pro- tect against emanation attacks are known as Transient Electromagnetic Pulse Equipment Shielding Techniques TEMPEST devices. TEMPEST was originally a government research study aimed at protecting electronic equipment from damage from the electromagnetic pulse EMP from nuclear explosions. It has since expanded to a general study of monitoring emanations and preventing ema- nation interception. Thus TEMPEST is now a formal name referencing a broad category of activities rather than an acronym for a specific purpose. TEMPEST Countermeasures Some TEMPEST countermeasures are Faraday cages, white noise, and control zones. A Faraday cage is a box, mobile room, or entire building that is designed with an external metal skin, often a wire mesh, that fully surrounds an area on all six sides i.e., front, back, left, right, top, and bottom. This metal skin is slightly electrified to produce a capacitor-like effect hence the name Faraday that prevents all electromagnetic signals emanations from exiting or entering the area enclosed by the Faraday cage. Faraday cages are very effective in blocking EM signals. In fact, inside of an active Faraday cage, mobile phones do not work and neither can you pick up broadcast radio or television stations. White noise is simply the broadcasting of false traffic at all times to mask and hide the pres- ence of real emanations. White noise can consist of a real signal of another source that is not