The power to restrict or allow passage to or through an object, via a barrier, using something a person has and /or something a person knows.
A simple form of access control is the use of a mechanical lock and a key. The door is the barrier, the restriction is if you have a key or not and the object is the space on the other side of the door.
Both the object and the barrier may be real or imaginary devices. The barrier may be a software feature that does not allow you access to information without the key.
Also some barriers are not concerned so much about controlling the passage of a person so much as controlling access to a persons vehicle e.g. a boom gate.
Access Control can be differentiated into two main types; Physical Access Control and Logical Access Control.
Physical Access Control is about accessibility of space. Access to buildings, rooms and floors is access to certain spaces. The accessibility of these spaces is controlled usually by a key or token, which is the something you have, and can lend to someone else. Sometimes you also have to know a password or user name (something you know). A point of access may be setup so that during work hours a password will allow access but after hours access is dependant upon both the presentation of a valid token as well as a password or PIN.
These spaces may be subdivided into areas or cells so that your access is further restricted by the systems knowledge of where a person should within the system of cells and areas. When a system is setup like this it is important that personnel do not tailgate or follow another person either into or out of a door or If this tail-gating occurs then the system will assume that the person is still within an area and that they may have passed back their key to someone else when they entered and there fore will not allow that key to access doors etc that it would otherwise be valid for. Hence this feature is called Anti-Passback.
In high security installations there is also a feature called Dual Custody or Dual Key Entry. This simply means that two valid keys have to be presented to the reader within a certain time for access to be granted. This is often used in cash, drug or evidence vaults.
Sometimes as well as providing access to the space there may be other elements that are also accessed. These other elements may be air conditioning, lighting, PABX location, alarm disarming, a CCTV state etc. The access control may also change due to specific alarm events like fire, bomb threat or other emergency condition.
Access Control Tokens(Graphics in this link) are available in many different technologies and in many different shapes. The information that is stored on the token is presented to a reader that reads the information and sends it on to the system for processing. The token may have to be swiped, inserted or placed on or near a reader. The reader sends information to the system. This usually consists of something that identifies the token as belonging to the system as well as something unique that identifies the token itself. The system will then decide if access is to be granted or denied based upon the validity of the token for the point where it is read based upon time, date, day, holiday or other condition that is used for controlling validation.
When Biometric readers are used then the token or key is your retina, fingerprint, hand geometry, voice or whatever biological attribute is tested. Again this is something you have. Most biometric readers also require a PIN as this is used to index the stored data on the sample readings of your biological attribute.
Physical Access Control is not restricted to humans. Vehicles often will have active access control devices fitted to them so that they are treated independently to the driver. This enables identification for parking, fuel, weigh bridge and can even be used to check over speed limit conditions. Also access control is being used with animals, both in the domestic situation (e.g. the cat/dog door - You cat/dog gets in others don't) and in the commercial scene like in dairies where they not only allow access but can be utilised to measure production against each individual member of the heard.
Here we are mainly concerned with information and its integrity. The access can be obtained again from a token and/or a password.
The common old Personnel Computer used to come with a key switch on the front. This switch was used to lock out the keyboard so that others could not use or access information on the PC. Although this is fairly primitive it is a form of intellectual access control
The use of dongles (something you plug into a computer port to control access to a certain program or program properties) has become quite common. Also the use of a reader on a computer that allows access to the computer and/or parts thereof is also becoming more common. Passwords and/or tokens are also being used to allow access to databases, networks and parts of networks (Domains).
The rights that are given may be quite complex overall, but essentially they are concerned with whether a person is allowed to view the data only, or have permission to modify it as well.
Most of the networking systems that are used by companies and government use a system of user names and passwords to provide access control of the various elements of the network.
DKS have a number of systems for protecting access to information. These range from AUTO LAN Keys to Pre-Paid access keys for Information Sellers. We also can provide software protection to protect the copyright on software products.
Our main specialisation is in access control. We supply and install many different brands of systems and types of systems. We have various standalone systems, which feature a single door, to systems that are Australia Wide, with hundreds of controlled access points.
Our new systems using contact less smart cards can connect together via a TCP/ IP network. This means that expensive and slow land lines can be forgotten and existing infrastructure can be utilised for the programming and monitoring of large systems. If the network traffic is not overloaded, your CCTV can also be streamed across the network so that an operator can see exactly what is going on at a remote site.