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For access control on a highway, see limited-access highway. * * * * * * * * * * * * * * * * * * * * * * Before adding any more images to this * * page please do carefully consider * * whether they would be mere decoration * * or actually improve A limited-access road or controlled-access road is a Road to which access from adjacent properties is limited in some way


Access control is the ability to permit or deny the use of a particular resource by a particular entity. Access control mechanisms can be used in managing physical resources (such as a movie theater, to which only ticketholders should be admitted), logical resources (a bank account, with a limited number of people authorized to make a withdrawal), or digital resources (for example, a private text document on a computer, which only certain users should be able to read).

Item Control or Physical Key Management is an area within (and possibly integrated with)an access control system which concerns the managing of possession and location of small assets or physical (mechanical) keys.

Contents

Physical access

Underground entrance to the New York City Subway system
Underground entrance to the New York City Subway system

Physical access of a person may be allowed depending on payment, authorization, etc. The City of New York Admission to a journey or other event or establishment may be subject to paying an entrance fee / buying a ticket. Also there may be one-way traffic of people. These can be enforced by personnel such as a border guard, a doorman, a ticket checker, etc. Border Guard, Border Patrol, Border police, or Frontier police is a National security agency that performs Border control, i A ticket is a Voucher to indicate that one has paid for Admission to an event or establishment such as a Theatre, Movie theater, Amusement , or with a device such as a turnstile. A turnstile, also called a baffle gate, is a form of Gate which allows one person to pass at a time There may be fences to avoid circumventing this access control. A fence is a freestanding structure designed to restrict or prevent movement across a boundary An alternative of access control in the strict sense (physically controlling access itself) is a system of checking authorized presence, see e. g. Ticket controller (transportation). A ticket controller is a person who randomly checks tickets on Public transport in systems where one can enter the Vehicle without being checked ( Proof-of-payment A variant is exit control, e. g. of a shop (checkout) or a country. Point of sale or point of service ( POS or PoS) can mean a retail shop, a checkout counter in a shop or the location where a transaction

In physical security, the term access control refers to the practice of restricting entrance to a property, a building, or a room to authorized persons. Physical security describes measures that prevent or deter Attackers from accessing a facility resource or information stored on physical media Physical access control can be achieved by a human (a guard, bouncer, or receptionist), through mechanical means such as locks and keys, or through technological means such as access control systems. Within these environments, physical key management may also be employed as a means of further managing and monitoring access to mechanically keyed areas or access to certain small assets.

Physical access control is a matter of who, where, and when. An access control system determines who is allowed to enter or exit, where they are allowed to exit or enter, and when they are allowed to enter or exit. Historically this was partially accomplished through keys and locks. When a door is locked only someone with a key can enter through the door depending on how the lock is configured. Mechanical locks and keys do not allow restriction of the key holder to specific times or dates. Mechanical locks and keys do not provide records of the key used on any specific door and the keys can be easily copied or transferred to an unauthorized person. When a mechanical key is lost or the key holder is no longer authorized to use the protected area, the locks must re-keyed.

Electronic access control uses computers to solve the limitations of mechanical locks and keys. A wide range of credentials can be used to replace mechanical keys. A credential is an attestation of qualification competence or authority issued to an individual by a third party with a relevant de jure or de facto authority or The electronic access control system grants access based on the credential presented. When access is granted, the door is unlocked for a predetermined time and the transaction is recorded. When access is refused, the door remains locked and the attempted access is recorded. The system will also monitor the door and alarm if the door is forced open or held open too long after being unlocked.

Access Control System Operation

When a credential is presented to a reader, the reader sends the credential’s information, usually a number, to a control panel, a highly reliable processor. The control panel compares the credential's number to an access control list, grants or denies the presented request, and sends a transaction log to a database. When access is denied based on the access control list the door remains locked. If there is a match between the credential and the access control list, the control panel operates a relay that in turn, unlocks the door. The control panel also ignores a door open signal to prevent an alarm. Often the reader provides feedback, such as a flashing red LED for an access denied and a flashing green LED for an access granted.

The above description is a single factor transaction. Credential's can be passed around thus subverting the access control list. For example Alice has access rights to the server room but Bob does not. Alice either gives Bob her credential or Bob takes it -- he now has access to the server room. To prevent this two-factor authentication can be used. In a two factor transaction, the presented credential and a second factor are needed for an access granted. The second factor can be a PIN, a second credential, operator intervention, or a biometric input. Often the factors are characterized as 1. )Something you have, a credential, 2. )Something you know, a PIN, or 3. )Something you are, a biometric input.

Access Control System Components

An access control point, which can be a door, turnstile, parking gate, elevator, or other physical barrier where granting access can be electrically controlled. A door is a panel or barrier usually hinged or sliding that is used to cover an opening in a Wall or partition going into a building or space Typically the access point is a door. An electronic access control door can contain several elements. At its most basic there is an electric lock (see electronic lock. An electronic lock (more precisely an electric lock is a locking device which operates by means of electric current ) The lock is unlocked by an operator with a switch. To automate this, operator intervention is replaced by a reader. The reader could be a keypad where a code is entered, it could be a card reader, or it could be a biometric reader. A memory card reader is a device used for communication with a Smart card or a flash Memory card. Readers do not usually make an access decision but send a card number to an access control panel that verifies the number against an access list. To monitor the door position a magnetic door switch is used. In concept the door switch is not unlike those on refrigerators or car doors. Generally only entry is controlled and exit is uncontrolled. In cases where exit is also controlled a second reader is used on the opposite side of the door. In cases where exit is not controlled, free exit, a device called a request-to-exit (REX) is used. Request-to-exit devices can be a pushbutton or a motion detector. When the button is pushed or the motion detector detects motion at the door, the door alarm is temporarily ignored while the door is opened. Exiting a door without having to electrically unlock the door is called mechanical free egress. This is an important safety feature. In cases where the lock must be electrically unlocked on exit, the request-to-exit device also unlocks the door.

Credential

A credential is something you know, such as number or PIN, something you have, such as an access badge, something you are, such as a biometric feature, or some combination of these. An access badge is a Credential used to gain entry to an area having automated Access control entry points The typical credential is an access card, key fob, or other key. There are many card technologies including magnetic stripe, bar code, Wiegand, 125 kHz proximity, contact smart cards, and contactless smart cards. Typical biometric technologies include fingerprint, facial recognition, iris recognition, retinal scan, voice, and hand geometry.

Bar Code Technology

A bar code is a series of alternating dark and light stripes that are read by an optical scanner. The organization and width of the lines is determined by the bar code protocol selected. There are many different protocols but code 39 is the most popular in the security industry. Sometimes the digits represented by the dark and light bars are also printed to allow people to read the number without an optical reader. The advantage of using bar code technology is that it is cheap and easy to generate the credential and it can easily be applied to cards or other items. The disadvantage of this technology is that it is cheap and easy to generate a credential making the technology susceptible to fraud and the optical reader can have reliability problems with dirty or smudged credentials. One attempt to reduce fraud is to print the bar code using carbon-based ink and then cover the bar code with a dark red overlay. The bar code can then be read with an optical reader tuned to the infrared spectrum, but can not easily be copied by a copy machine. This does not address the ease with which bar code numbers can be generated from a computer using almost any printer.

Magnetic Stripe Technology

Magnetic stripe technology, usually called mag-stripe, is so named because of the stripe of magnetic oxide tape that is laminated on a card. There are three tracks of data on the magnetic stripe. Typically the data on each of the tracks follows a specific encoding standard, but it is possible to encode any format on any track. A mag-stripe card is cheap compared to other card technologies and is easy to program. The magnetic stripe holds more data than a bar code can in the same space. While a mag-stripe is more difficult to generate than a bar code, the technology for reading and encoding data on a mag-stripe is widespread and easy to acquire. Magnetic stripe technology is also susceptible to misreads, card wear, and data corruption.

Wiegand Card Technology

Wiegand card technology is a patented technology using embedded ferromagnetic wires strategically positioned to create a unique pattern that generates the

Proximity Card Technology

The Wiegand effect was used in early access cards. The Wiegand interface is a De facto wiring standard which arose from the popularity of Wiegand effect card readers in the 1980s Ferromagnetism is the basic mechanism by which certain materials (such as Iron) form Permanent magnets and/or exhibit strong interactions with Magnets it The Wiegand effect is named after its discoverer John R Wiegand. This method was abandoned in favor of other technologies. The new technologies retained the Wiegand upstream data so that the new readers were compatible with old systems. Readers are still called Wiegand but no longer use the Wiegand effect. A Wiegand reader radiates a 1" to 5" electrical field around itself. Cards use a simple LC circuit. An LC circuit is a variety of resonant circuit or tuned circuit and consists of an Inductor, represented by the letter L and a Capacitor, represented When a card is presented to the reader, the reader's electrical field excites a coil in the card. The coil charges a capacitor and in turn powers a integrated circuit. A capacitor is a passive electrical component that can store Energy in the Electric field between a pair of conductors Microchipsjpg|right|thumb|200px|Microchips ( EPROM memory with a transparent window showing the integrated circuit inside The integrated circuit outputs the card number to the coil which transmits it to the reader.

A common proximity format is 26 bit Wiegand. This format uses a facility code or sometimes called a site code. The facility code is unique number common to all of the cards in a particular set. The idea is an organization will have there own facility code and then numbered cards incrementing from 1. Another organization has a different facility code and their card set also increments from 1. Thus different organizations can have card sets with the same card numbers but since the facility codes differ, the cards only work at one organization. This idea worked fine for a while but there is no governing body controlling card numbers, different manufacturers can supply cards with identical facility codes and identical card numbers to different organizations. Thus there is a problem of duplicate cards. To counteract this problem some manufacturers have created formats beyond 26 bit Wiegand that they control and issue to organization.

In the 26 bit Wiegand format bit 1 is an even parity bit. Bits 2-9 are a facility code. Bits 10-25 are the card number. Bit 26 is an odd parity bit. Other formats have a similar structure of leading facility code followed by card number and including parity bits for error checking

Smart Card

There are two types of smart cards: contact and contactless. Both have an embedded microprocessor and memory. The smart card differs from the card typically called a proximity card in that the microchip in the proximity card has only one function: to provide the reader with the card’s identification number. The processor on the smart card has an operating system and can handle multiple applications such as a cash card, a pre-paid membership card, and even an access control card. The difference between the two types of smart cards is found in the manner with which the microprocessor on the card communicates with the outside world. A contact smart card has eight contacts, which must physically touch contacts on the reader to convey information between them. A contactless smart card uses the same radio-based technology as the proximity card with the exception of the frequency band used. Smart cards allow the access control system to save user information on a credential carried by the user rather than requiring more memory on each controller.

PIN

A personal identification number (PIN) falls in the category of what you know rather than what you have. The PIN is usually a number consisting of four to eight digits. Less and the number is too easy to guess. More and the number is too difficult to remember. The advantage to using a PIN as an access credential is that once the number is memorized, the credential cannot be lost or left somewhere. The disadvantage is the difficulty some people have in remembering numbers that are not frequently used and the ease with which a PIN can be observed and therefore used by unauthorized people. The PIN is even less secure than a bar code or magnetic stripe card.

Computer security

In computer security, access control includes authentication, authorization and audit. This article describes how security can be achieved through design and engineering Authentication (from Greek αυθεντικός real or genuine from authentes author is the act of establishing or confirming something (or someone as An audit trail or audit log is a chronological sequence of audit records each of which contains evidence directly pertaining to and resulting from the execution of a business process or It also includes measures such as physical devices, including biometric scans and metal locks, hidden paths, digital signatures, encryption, social barriers, and monitoring by humans and automated systems. A lock is a mechanical fastening device which may be used on a Door, Vehicle, or container restricting access to the area or Property enclosed A digital signature or digital signature scheme is a type of asymmetric cryptography used to simulate the security properties of a handwritten Signature

In any access control model, the entities that can perform actions in the system are called subjects, and the entities representing resources to which access may need to be controlled are called objects (see also Access Control Matrix). Access Control Matrix or Access Matrix is an abstract formal computer protection It is the most general description of Operating system Protection Subjects and objects should both be considered as software entities, rather than as human users: any human user can only have an effect on the system via the software entities that they control. Although some systems equate subjects with user IDs, so that all processes started by a user by default have the same authority, this level of control is not fine-grained enough to satisfy the Principle of least privilege, and arguably is responsible for the prevalence of malware in such systems (see computer insecurity). In Information security, Computer science, and other fields the principle of least privilege, also known as the principle of minimal privilege or just Malware, a Portmanteau word from the words '''mal'''icious and soft'''ware''', is software designed to infiltrate or damage a computer system without Many current Computer systems have only limited security precautions in place

In some models, for example the object-capability model, any software entity can potentially act as both a subject and object. The object-capability model is a Computer security model based on an object-oriented model of computation

Access control models used by current systems tend to fall into one of two classes: those based on capabilities and those based on access control lists (ACLs). Capability-based security is a concept in the design of Secure computing systems In Computer security, an access control list ( ACL) is a list of permissions attached to an object In a capability-based model, holding an unforgeable reference or capability to an object provides access to the object (roughly analogous to how possession of your house key grants you access to your house); access is conveyed to another party by transmitting such a capability over a secure channel. In an ACL-based model, a subject's access to an object depends on whether its identity is on a list associated with the object (roughly analogous to how a bouncer at a private party would check your ID to see if your name is on the guest list); access is conveyed by editing the list. (Different ACL systems have a variety of different conventions regarding who or what is responsible for editing the list and how it is edited. )

Both capability-based and ACL-based models have mechanisms to allow access rights to be granted to all members of a group of subjects (often the group is itself modeled as a subject).

Access control systems provide the essential services of identification and authentication (I&A), authorization, and accountability where:

Identification and authentication (I&A)

Identification and authentication (I&A) is the process of verifying that an identity is bound to the entity that asserts it. The I&A process assumes that there was an initial vetting of the identity, during which an authenticator was established. Subsequently, the entity asserts an identity together with an authenticator as a means for validation. The only requirements for the identifier is that it must be unique within its security domain.

Authenticators are commonly based on at least one of these four factors:

Authorization

Authorization applies to subjects rather than to users (the association between a user and the subjects initially controlled by that user having been determined by I&A). Authorization determines what a subject can do on the system.

Most modern operating systems define sets of permissions that are variations or extensions of three basic types of access:

These rights and permissions are implemented differently in systems based on discretionary access control (DAC) and mandatory access control (MAC).

Accountability

Accountability uses such system components as audit trails (records) and logs to associate a subject with its actions. The information recorded should be sufficient to map the subject to a controlling user. Audit trails and logs are important for

If no one is regularly reviewing your logs and they are not maintained in a secure and consistent manner, they may not be admissible as evidence.

Many systems can generate automated reports based on certain predefined criteria or thresholds, known as clipping levels. For example, a clipping level may be set to generate a report for the following:

These reports help a system administrator or security administrator to more easily identify possible break-in attempts.

Access Control Techniques

Access control techniques are sometimes categorized as either discretionary or non-discretionary. The three most widely recognized models are Discretionary Access Control (DAC), Mandatory Access Control (MAC), and Role Based Access Control (RBAC). MAC and RBAC are both non-discretionary.

Discretionary Access Control

Discretionary access control (DAC) is an access policy determined by the owner of an object. In Computer security, discretionary access control ( DAC) is a kind of Access control defined by the Trusted Computer System Evaluation Criteria The owner decides who is allowed to access the object and what privileges they have.

Two important concepts in DAC are

Access controls may be discretionary in ACL-based or capability-based access control systems. In Computer security, an access control list ( ACL) is a list of permissions attached to an object Capability-based security is a concept in the design of Secure computing systems (In capability-based systems, there is usually no explicit concept of 'owner', but the creator of an object has a similar degree of control over its access policy. )

Mandatory Access Control

Mandatory access control (MAC) is an access policy determined by the system, not the owner. In Computer security, mandatory access control ( MAC) refers to a type of Access control by which the operating system constrains the ability of a subject MAC is used in multilevel systems that process highly sensitive data, such as classified government and military information. A multilevel system is a single computer system that handles multiple classification levels between subjects and objects.

Two methods are commonly used for applying mandatory access control:

Few systems implement MAC. XTS-400 is an example of one that does. The XTS-400 is a multi-level secure computer system It is Multi-user and multi-tasking.


Role Based Access Control

Role-based access control (RBAC) is an access policy determined by the system, not the owner. In computer systems security role-based access control ( RBAC) is an approach to restricting system access to authorized users RBAC is used in commercial applications and also in military systems, where multi-level security requirements may also exist. RBAC differs from DAC in that DAC allows users to control access to their resources, while in RBAC, access is controlled at the system level, outside of the user's control. Although RBAC is non-discretionary, it can be distinguished from MAC primarily in the way permissions are handled. MAC controls read and write permissions based on a user's clearance level and additional labels. RBAC controls collections of permissions that may include complex operations such as an e-commerce transaction, or may be as simple as read or write. A role in RBAC can be viewed as a set of permissions.

Three primary rules are defined for RBAC:

1. Role assignment: A subject can execute a transaction only if the subject has selected or been assigned a role.

2. Role authorization: A subject's active role must be authorized for the subject. With rule 1 above, this rule ensures that users can take on only roles for which they are authorized.

3. Transaction authorization: A subject can execute a transaction only if the transaction is authorized for the subject's active role. With rules 1 and 2, this rule ensures that users can execute only transactions for which they are authorized.

Additional constraints may be applied as well, and roles can be combined in a hierarchy where higher-level roles subsume permissions owned by sub-roles.

Most IT vendors offer RBAC in one or more products.



Telecommunication

In telecommunication, the term access control is defined in U. S. Federal Standard 1037C [1] with the following meanings:

  1. A service feature or technique used to permit or deny use of the components of a communication system. Federal Standard 1037C, entitled Telecommunications Glossary of Telecommunication Terms is a United States Federal Standard issued by the General Services Administration System (from Latin systēma, in turn from Greek systēma is a set of interacting or interdependent Entities, real or abstract
  2. A technique used to define or restrict the rights of individuals or application programs to obtain data from, or place data onto, a storage device. Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's A data storage device is a device for recording (storing information (data
  3. The definition or restriction of the rights of individuals or application programs to obtain data from, or place data into, a storage device.
  4. The process of limiting access to the resources of an AIS to authorized users, programs, processes, or other systems.
  5. That function performed by the resource controller that allocates system resources to satisfy user requests. In Telecommunications, a user is a person organization or other entity that employs the services provided by a Telecommunication system or by an Information

Notice that this definition depends on several other technical terms from Federal Standard 1037C.

Public Policy

In public policy, access control to restrict access to systems ("authorization") or to track or monitor behavior within systems ("accountability") is an implementation feature of using trusted systems for security or social control. Accountability is a concept in Ethics with several meanings It is often used synonymously with such concepts as answerability enforcement responsibility, blameworthiness In the Security engineering subspecialty of Computer science, a trusted system is a system that is relied upon to a specified extent to enforce a specified security Security is the condition of being protected against danger loss and criminals Social control refers to social mechanisms that regulate individual and group behavior leading to conformity and compliances to the rules of a given Society or

See also

References

External links

Dictionary

access control

-noun

  1. The practice of restricting entrance to a property, a building, or a room to authorized persons.
  2. In technology, permiting or denying the use of a particular resource.
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