Access control can be defined as the objects, methods and actions used to restrict access to a door, room, area or building to authorized persons only. The elements of an access control system can simply be expressed as:

• who: a unique person or group of people
• what: something preventing/blocking access i.e a lock; and something to grant/clear access, i.e. a key (credential)
• where: a space restriction
• when: a time restriction

Access control examples include:

1. Controlling which person/s (who) has access to a secure area behind a locked door (where) using a key (what; credential), anytime (when).

2. Controlling which person/s (who) may enter a theater (where) using a ticket (credential), at the start of the show (time restriction to seat guests)

So what does this have to do with electronic security, and how does this help solve security issues in my enterprise?

Access control systems have been in use since the advent of doors with locks and keys. Even though locks and keys have been traditionally used to provide basic access control, this now traditional form of access control has its limitations; in example 1, the person may loose or lend the key, giving access to the secure area to another person...

An access control system in the context of electronic security helps solve the limitations of traditional access control. A basic access control system in electronic security terms has three main components

1. A unique user (person or group) with unique credential/s (cards, fobs, tags, PIN, passcode, fingerprint, etc)

2. A door, gate, shutter, lift or car park secured by electronic means (eg, electric door strike fitted to a door with a card reader fitted to the door frame) restricting access to an area that is compatible with the chosen credentials

3. Some form of control panel or computer to receive credential information (eg a card number from a card reader at a secure door) and grant access when a unique user presents a valid credential (eg a current card or valid PIN)

Using access control systems in electronic security allows the automation and control of doors, gates and lifts.

How electronic security access control systems differ is based on the types of credentials to be used and the method the credentials are authenticated, allowing access.