What is Access Control System?
A typical form of security technique used for regulating selective access with restriction in a specific computing environment is called access control system. The power of accessing any resource is technically called as authorization.
Specific analogous mechanisms which are used for access control system are Login credentials’ and locks.
Access control system is used geographically by personnel in the role of border guard, ticket checker and bouncer and they make use of specific device like turnstile. Uses of fences are done in some areas in order to avoid obstruction of access control.
Access control system is used for creating a restriction in the entry point of any property, any building, or even a room of any authorized persons. Physical control of access can be created by an individual via mechanical support like locks and keys or even with use of technology in the form of access control systems. One of the common systems is mantrap. Access control system is used for determining the fact as who can enter and exit, in which place one can enter or exit and when one can enter or exit. In case a door is found locked then one who is having the key can enter through door. Mechanical locks and keys do not possess any specific restriction and don’t provide any record as how many times the keys used on any particular door. A duplicate key can be made and transferred to a person who is not authorized to open it. In case of key loss or change of authorized person, the Re- Keying of the lock need to be done.
Electronic access control system with support of computers can be used to replace the disadvantages associated with mechanically designed locks and keys. A good variety of credentials can be applied for replacement of mechanical lock and keys. This system provides access depending on the credentials presented. When access is given to an individual the door remains opened for a certain period which is fixed and the entry gets electronically recorded in system. The access control system will intimate if in case it detects that the door is opened forcefully and remained open for a longer duration than decided.
Operation of Access control system:
The point of time in which a special credential is given to a reader, the reader acts towards providing the information related to the credential. And in maximum cases in the form of a number to control panel. A control panel is a very reliable processor which goes for comparing of credential with list of access control. Either it gives permission or denies permission and send a log for transaction in the database. In case of access denied the door remains locked. The reader indicates with green LED in case of access granted and with red LED in case of access denied.
This is a transaction of single factor. Take an example when Rex is having the permission for entering server room, but his friend Ken is not having it. Rex has the option with him to make opportunity for Ken to enter the server room. He can share his credentials to let Ken enter the room. To prevent such activity application of two factor authentication can be done. In this case there will be need of first credential plus another factor to get access. In this case a PIN can be another credential or biometric input.
There are 3 types of information for authentication:
User’s identity can be detected with use of passwords.
Credential of Access control System
Credential is a specialized info that gives power to an individual to get access to a specialized zone or an information system which is computer based. A well defined credential is the one which is something which an individual is aware of, something which is available with the authorized individual or it can also be something which is present there in the authorized person (Biometric Thumb Impression). On the other end it can be combination of all three. This form of credential is popularly called as multi-factor authentication. Credentials can be in the form of access card or access devices.
Access control system components
What is an access control point? It can appear to an individual in different forms like a door, parking gate, turnstile, elevator, or it can even be a fence barrier. To cross the control point an individual need to get permission from the electronically controlled access system. In maximum cases the point of access is a door. There are several elements which are present in electronic access control system door. A stand-alone electric lock is associated with it and which can only be unlocked with support of a switch instructed by an operator. To make this concept an automatic one, a reader is introduced in place of an operator. Three types of reader can be installed for automatic performance: The first one can be keypad in which individual need to enter a special code, second one can be a card reader and at last application of biometric reader can also be done.
The reader doesn’t process the power to give access to any individual. It sends a special card number for verification by the Access control system. The number is verified with an access list. For monitoring the position of the door application of a door switch which is magnetic in nature can be used. The magnetic switch will have control only on entry, and exit will remain uncontrolled by the switch. To keep a control on the exit of the door a separate reader need to be used on the other side of the door.
If there is no need to control the exit from door and free exit is welcome then installation of device named REX (Request to Exit) can be installed. Use of push-button or a detector of motion is done in REX.
Access control system topology
It is now clear that decisions of access control are taken only after comparing the given credentials with available list of access control the decision and comparing of credentials with access list is done by the server or a host with support of an Access control system panel or even with use of a reader.
Types of readers:
The classifications of the available types of Access control system panel readers are done depending on the functionality.
Some Readers are available in market with additional features like LCD and function buttons used for purposes like data collection, for intercom camera, speaker and microphone and support for read and write for smart card. The readers can also be classified based on the type of technology used for identification.
Access control system topologies:
1. Serial controllers. Here the controller gets connected to a host PC through serial RS-485 line of communication.
◈ Takes short time for response
◈ Offers High security and reliability
◈ Large volume of data cannot be transferred through RS-485
◈ Special serial switches are needed for Serial controllers
◈ Host PC is not allowed for communicating with more than one controller at a time
◈ RS-485 is more expensive than Category 5 UTP network cable
2. Serial main and sub-controllers: Almost all hardware’s for door are usually connected with sub-controllers. It forwards requests to main controllers for decision.
◈ Less expensive system
◈ Specific models of this type of controllers fail to access decisions independently
◈ Serial main and sub-controllers are expensive.
◈ Consist of all above-mentioned disadvantages associated with RS-485
3. Serial main controllers & intelligent readers: All hardware of door gets connected with intelligent or semi-intelligent readers directly with an access control system. Here the decision for access is not taken by the reader and gets forwarded straight to main controller. In special case when there is no connection with main controller, the user needs to make use of the internal database for recording of events and to access decisions. Readers that are semi-intelligent and having no access to database and cannot perform without presence of main controller can be used in areas where there is no need of security of higher level. The main controller supports readers ranging from 16 to 64.
4. Serial controllers with terminal servers: Although there is huge development in the field of technology with a good percentage of increase in the use of computers still the access control system manufacturers of the industry preferred to remain conservative in their approach and did not prefer to go for products which are network-enabled. When requested hard for providing solutions for network connectivity, many of them prefer to go with the option which is less difficult and need less effort. The process seems simple with introduction of a terminal server which is a typical form of device used for converting serial data through LAN or WAN. RS-485 advantages, as well as disadvantages, are application in this controller.
5. IP controllers: This access control system gets connected with host PC through Ethernet LAN or WAN
6. IP readers: This reader gets connected with host PC through Ethernet LAN or WAN
The most common protection risk of intrusion using an access control system is by use of a reliable user via a door, and this is known as "tailgating."
The second and one of the most common risk is there with levering the door open
The third and one of the sensitive security risks for an access control system is from natural disasters.
Security of computer access control includes the following:
To make the definition even more perfect, access control will take care of access approval and the system will make the decision for granting permission or rejecting the request of access requested by an authenticated subject, taking into consideration the fact as what exactly the subject is authorized for accessing.
Access control system is sometimes clubbed with authentication to form a single operation so that the access requested can be approved based on authentication successfully or may be based on access token which is anonymous. Authentication methods may include: