Physical Security in Computer Systems

In physical security, guards add a dynamic, human element to the control process. Unlike the static nature of other controls, humans are responsive and able to make decisions based on the situation. If trained correctly they provide the most flexible options for security. For this reason, they can be the most expensive controls to deploy.

Dogs provide two additional benefits in security. Their enhanced senses can be utilized to detect certain threats that a human may not. Additionally, dogs provide an added layer of protection to prevent the harm of human. If managed correctly, dogs can be a great help in protecting valuable resources.

Lock Systems

Manual - locks such as padlocks and combination locks; these locks are often preset by the manufacturer and difficult to alter once in place. They are often suitable for control of access to a single door.

Programmable - often combination locks of some kind; these locks are programmable for use by the owner and can have a key or code change at any time. These are often used for access to computer rooms because the codes are easily reset and require no electricity.

Electronic - these locks function with some electronic mechanism. This allows the locks to function with other electronic systems such as alarm systems. These locks can be controlled from a distance by a guard or even track controls through use of ID cards and a computer system. They are useful for a wide range of applications and are often used for building access.

Biometric - locks such as finger/palm readers or retina scanners; these are the most sophisticated locks and can be used to guard the most secure areas as well as controlling general employee access.

Alarm Systems

One of the most common alarms is the burglar alarm. This alarm is used to detect unauthorized intrusions into restricted areas. The alarm utilizes a variety of sensors such as motion detectors, thermal detectors, contact and weight sensors, and vibration sensors.

The Most Serious Physical Security Threat

Perhaps the most serious threat to physical security rests on the shoulders of fires. Fires not only threaten an organization's facility and resources, but also the lives of the people who work there. Because of the additional threat to human life, it is important to have fire protection systems ready to respond to any potential harm.

Interception Techniques

Many interceptions techniques fall into the realm of physical security as they may involve some physical way of gaining access to information. They range from directly viewing sensitive information to reconstruction of data based on captured signals. Physical security can take steps to eliminate these potential threats. Below is a list of interception methods:

Direct observation - this method involves the interceptor to get close enough to information to directly observe it. The best protection against this is to keep sensitive information both restricted to authorized users as well as authorized locations.

Interception of data transmissions - this method involves the interceptor accessing data that is in transit, often over the internet or LAN. Tapping into cables is also a method of this interception. Protection against these threats varies. Physical inspection of ports and activity logs can help determine if unauthorized access has been gained. Fiber optic cables make tapping wires and cables much more difficult.

Electromagnetic interception - a much debated topic, this method involves eavesdropping on the electromagnetic (EM) signals of devices. The theory is that images and information could be reconstructed from electromagnetic radiation waves. While this method is not so commonplace there are protection schemes being developed. These may involve location of computers and special shielding.