Chapter 5: Physical and Environmental Security

• Physical security has a different set of vulnerabilities, threats, and countermeasures from a computer and information security. Physical security deals with physical destruction, intruders, environmental issues, theft, and vandalism. Therefore, when security professionals look at physical security they, they are conserved with how people can physically enter an environment and cause damages. 
• Threats that an organization faces falls into these broad categories:
• Natural environment threats: flood, earthquakes, storms, tornadoes etc.
• Supply system threats: power distribution outages, communications interruptions and interruption of other resources (water, gas, air filtration etc.).
• Manmade threats: unauthorized access (both internal and external), explosions, damage by disgruntled employees, employee errors and accidents, vandalism, fraud, theft etc. 
• Politically motivated threats: strikes, riots, civil disobedience, terrorist attacks, bombings etc.
• The primary consideration above all is that nothing should impede life safety goals, so protecting human life is the first priority.
• Physical security program should comprise safety and security mechanisms.
• Safety deals with the protection of life and assets against fire, natural disasters, and devastating accidents. It addresses vandalism, theft, and attacks by individuals.
• Physical security must be implement based on layered defense model, the physical controls should work together in tiered architecture.