Physical security

Physical security describes security measures that are designed to deny unauthorized access to facilities, equipment, and resources and to protect personnel and property from damage or harm (such as espionage, theft, or terrorist attacks). Physical security involves the use of multiple layers of interdependent systems that can include CCTV surveillance, security guards, protective barriers, locks, access control, perimeter intrusion detection, deterrent systems, fire protection, and other systems designed to protect persons and property. Physical security systems for protected facilities are generally intended to: deter potential intruders (e.g. warning signs, security lighting and perimeter markings); detect intrusions and monitor/record intruders (e.g. intruder alarms and CCTV systems); and trigger appropriate incident responses (e.g. by security guards and police). It is up to security designers, architects and analysts to balance security controls against risks, taking into account the costs of specifying, developing, testing, implementing, using, managing, monitoring and maintaining the controls, along with broader issues such as aesthetics, human rights, health and safety, and societal norms or conventions. Physical access security measures that are appropriate for a high security prison or a military site may be inappropriate in an office, a home or a vehicle, although the principles are similar. Natural surveillance and Crime prevention through environmental design The goal of deterrence methods is to convince potential attackers that a successful attack is unlikely due to strong defenses. The initial layer of security for a campus, building, office,, or other physical space uses crime prevention through environmental design to deter threats. Some of the most common examples are also the most basic: warning signs or window stickers, fences, vehicle barriers, vehicle height-restrictors, restricted access points, security lighting and trenches. Physical barriers such as fences, walls, and vehicle barriers act as the outermost layer of security.