Access control systems have a central brain (controller or panel) that sends instructions to locking hardware of various kinds. When an individual presents themselves at a controlled door and requests entrance, the access control system panel searches an internal database and determines whether or not that individual is authorized to enter. Upon entry, the system logs a date and time stamp with the identity of the individual so that a complete access history is stored. These logs can later be used for reference, to run reports, or any other function required by the owner.
There are many ways that an individual can authenticate themselves at an access controlled door to request entry. One of the most popular methods is proximity readers, also referred to as proximity cards or “prox cards”. Proximity readers provide each user a card or key fob that features a unique identification number. The reader is typically installed in the wall next to the door at a convenient height so that an individual requesting access can present their proximity card or key fob within a few inches of the reader. The reader then sends a signal to the access control system panel to request permission for that individual. If they are authorized to enter, the access control panel releases the locking device to allow entry. Typically, the lock will remain open for a number of seconds that is determined by the owner and then returns to its locked or secure state.
Other authentication technologies include keypads (code entry), voice activation systems, comparative weight detectors, and other biometric sensors. Although the authentication methods vary, the general process of requesting access between the reader and the access control system panel is the same. Each methodology has advantages and disadvantage as well as different levels of security. The other determining factor when deciding which type of sensors to use is budget. Access control sensors tend to follow the trend of most technical security system components in that increased levels of security and quality result in higher costs.
The most secure form of commonly used access control system authentication is accomplished using biometric sensors. Finger print readers, iris scanners, and retina scanners are common biometric-style sensors that use unique biometric identifiers to distinguish an individual. These types of sensors increase the sophistication and cost of the system, but provide an extremely high level of security. Proximity cards and similar devices offer extraordinary advantages when compared to using traditional keys, but can also be lost or stolen. On the contrary, biometric sensors rely on unique, physical characteristics of each authorized user ensuring they are present when requesting entry from the access control system.
One of the most commonly used access control system functions is the history log. This characteristic is very effective when trying to identify who entered a controlled area and when. Some organizations run access reports regularly and others simply enjoy the ability to access this information when needed, but it has proven to always be an appreciated system feature. Unlike security systems that rely on keys, an access control system records whose credentials were used to enter a controlled door every time someone enters or exits (assuming the system includes and requires an individual to query a reader to exit an access controlled space). There are many other benefits that access control systems provide that we will explore in future blogs.
Be sure to check out next Wednesday’s blog on The O where we will explore other aspects of technical security.
