Physical Security Devices | CompTIA Network+ N10-007 | 4.1

In this video you will learn about physical security devices such as:  motion detectors, video surveillance, asset tracking tags, tamper detection, badges, biometrics, smart cards, key fobs, & locks.


Motion Detection

Motion detection is the process of detecting a change in the position of an object relative to its surroundings or a change in the surroundings relative to an object.  It can be achieved by either mechanical or electronic methods.[1]  Motion can be detected by monitoring changes in:

  • Infrared light (passive & active sensors)
  • Visible light (video & camera systems)
  • Radio frequency energy (radar & microwave motion detection)
  • Sound (microphones, other acoustic sensors)
  • Kinetic energy (seismic sensors)
  • Magnetism (magnetic sensors)
  • WiFi signals

Video Surveillance

Video surveillance (also known as closed-circuit television, CCTV) is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors.  It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point, point-to-multipoint, or mesh wired or wireless links.  Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring.[2]

Asset Tracking Tags

Asset tracking refers to the method of tracking physical assets, either by scanning barcode labels attached to the assets or by using tags using GPS or RFID which broadcast their location.  These technologies can also be used for indoor tracking of persons wearing a tag.  Passive RFID tags broadcast their location but have limited transmission range (typically a few meters).  Longer-range “smart tags” use active-RFID where a radio transmitter is powered by a battery & can transmit up to 2000 meters in optimum conditions.  RFID-based Asset Tracking requires an infrastructure to be put in place before the whereabouts of tags may be ascertained.  An asset tracking system can record the location and usage of the assets & generate various reports.[3]

Tamper Detection

Tamper detection is the ability of a device to sense that an active attempt to compromise the device integrity or the data associated with the device is in progress; the detection of the threat may enable the device to initiate appropriate defensive actions.[4]



An access badge is a credential used to gain entry to an area having automated access control entry points.  Entry points may be doors, turnstiles, parking gates or other barriers.  Access badges use various technologies to identify the holder of the badge to an access control system.  The most common technologies are magnetic stripe, proximity, barcode, smart cards, & various biometric devices.[5]


A biometric device is a security identification and authentication device.  Such devices use automated methods of verifying or recognizing the identity of a living person based on a physiological or behavioral characteristic.  These characteristics include fingerprints, facial images, iris and voice recognition.[6]

Smart Cards

A smart card is a physical electronic authorization device, used to control access to a resource.  It is typically a plastic credit card-sized card with an embedded integrated (IC) chip.[7]  Many smart cards include a pattern of metal contacts to electrically connect to the internal chip.  Others are contactless, and some are both.  Smart cards can provide personal identification, authentication, data storage, and application processing.[8]  Applications include identification, financial, mobile phones, public transit, computer security, schools, & healthcare.  Smart cards may provide strong security authentication for single sign-on (SSO) within organizations.

Key Fobs

A key fob (also known as a hardware token), is an electronic lock that controls access to a building or vehicle without using a traditional mechanical key. They can contain RFID chips and may be used as part of a two-step authentication protocol the works as follows:

  • The key fob generates a code every 30 to 60 seconds.  Every time the code changes on the fob, it is also matched in an authentication server.
  • The user logs into the system or restricted area, using the generated access code displayed on the key fob’s LCD display.  The authentication server matches the current code and allows access.


Oftentimes, the simplest forms of security are the most effective; this is often the case with locks on all network areas & equipment.  Door locks, biometric locks, laptop cable locks, server locks, USB locks are all simple yet effective mechanisms for helping to secure network devices.


  1. Beal, V. (2007). Motion Detection. Webopedia.
  2. Romesh, V. (2005). Distance Education in Technological Age.
  3. Asset tracking. Wikipedia.
  4. Tilborg & Jajodia (2011). Tamper Detection. Encyclopedia of Cryptography and Security.
  5. Access badge. Wikipedia.
  6. Wayman, J.; Jain, A.; Maltonie, D.; Maio, D. (2005). An Introduction to Biometric Authentication Systems.
  7. ISO/IEC 7816-2:2007 Identification Cards. ISO.
  8. Multi-application Smart Cards. Cambridge University Press.