Bristol Access Control Services

The term door security or door security gate may refer to any of a range of measures used to strengthen doors against door breaching, ram-raiding and lock picking, and prevent crimes such as burglary and home invasions. Door security is used in commercial and government buildings, as well as in residential settings.

Some strengthened doors function as fire doors to prevent or inhibit the spread of fire.

Alarms — designed to warn of burglaries.

• Smart locks can be used to limit door access to only people with an electronic key fob or near-field communication device, like a smartphone.^[1] These devices are popular with landlords, who can enable and disable digital access without physically mailing out keys. The locks can log the times of entry, and can trigger an alarm if they are struck during a break-in attempt.
• Deadbolts — unlike common spring latches, the locking mechanism of these typically prevents the bolt from being retracted by force, or shimming, and it cannot be moved to the open position except by rotating the key.

• Strike plate reinforcement can involve reinforcing the strike plate and/or the door frame, to prevent the strike plate from being rammed out of the frame.^{[citation needed]}
• Door reinforcements — various products are made to prevent delamination and or splitting of the door. Sheet steel plate can be placed behind or under the deadbolt and wrap the door edge to prevent breaking the door around the deadbolt. Heavy duty products that place plates on either side the door tied together with screws or bolts can be used to prevent delamination.
• Door chains — allows the doors to be opened slightly to view outside while still remaining locked.
• Secondary, internal locks — sliding bolts, hooks and speciality latches, metal blocks or bars mounted internally.
• Hinge screws — longer or specialized screws that prevent the door from being simply pulled out after removing the hinge pins. Often the hinge pin itself is screwed, from the inside while the door is open, into the hinge to prevent removal of the hinge pin without first opening the door.

• Burglar deterrent CD or MP3 files — home occupancy sounds recorded on a CD; the CD is played when the home owner is away, to mimic the home occupancy activities.
• Door viewers — small fish-eye lenses that allow residents to view outside without opening the door.
• Door windows — there are three common methods to add security to windows in or beside doors: security bars and grates, security films (coatings applied to the glass in windows to reinforce it), or breakage resistant windows (plexiglas, lexan, and other glass replacement products).
• Visibility — most police departments recommend the clearance of shrubs from near doorways to reduce the chance of a burglar being hidden from public view.

The following are the types of doors typically used in residential applications: solid wood door, panel doors (hollow and solid core), metal skinned wood-edged doors and metal edge-wrapped doors, and Fiberglass doors (strongest of the residential type). Typically, door frames are solid wood. Residential doors also frequently contain wood.

Steel doors with Multi locking system are recommended by construction professionals as important equipment in your security checklist. This type of door often comes with a wooden finish to maintain a natural aesthetic in their external appearance.

Security tests by Consumer Reports Magazine in the 1990s found that many residential doors fail or delaminate when force is applied to them. Solid wood doors withstood more force than the very common metal skinned wood-edged doors used in newer construction. A broad range door manufacturer, Premdor (now Masonite) once stated in one of its 1990s brochures entitled "Premdor Entry Systems" page 6 that "The results of tests were overwhelming, Steel edged doors outperform wood-edged doors by a ratio of 7 to 1. When you consider the practically two-thirds of all illegal entries were made through doors... One hit of 100 lb [lbf] strike force broke the wood-edged stile and opened the door. To actually open the steel-edged door required 7 strikes of 100 lb pressure [force]." Most door manufactures offer a number of different types of doors with varying levels of strength.

Consumer Reports Magazine also reported in its test results that door frames often split with little force applied and lower quality deadbolts simply failed when force was applied to the door.

The Chula Vista Residential Burglary Reduction Project which studied over 1,000 incidents found that "methods found to have relatively low effectiveness included: sliding glass door braces, such as wooden dowels, as opposed to sliding door channel or pin locks; deadbolts installed in the front door only; and outdoor lights on dusk-to-dawn timers".^[2]

The Chula Vista Residential Burglary-Reduction Project yielded the following findings: "From victim interviews, we learned that in 87% of the break-ins that occurred when intruders defeated locked doors with tools such as screwdrivers or crowbars, the burglars targeted "the one door that had no deadbolt lock ... not one burglar attempted to break a double-pane window during the course of successful or attempted burglary."^[2]

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An access badge is a credential used to gain entry to an area having automated access control entry points. Entry points may be doors, turnstiles, parking gates or other barriers.

Access badges use various technologies to identify the holder of the badge to an access control system. The most common technologies are magnetic stripe, proximity, barcode, smart cards and various biometric devices. The magnetic stripe ID card was invented by Forrest Parry in 1960.^[1]

The access badge contains a number that is read by a card reader. This number is usually called the facility code and is programmed by the administrator. The number is sent to an access control system, a computer system that makes access control decisions based on information about the credential. If the credential is included in an access control list, the access control system unlocks the controlled access point. The transaction is stored in the system for later retrieval; reports can be generated showing the date/time the card was used to enter the controlled access point.

The Wiegand effect was used in early access cards. This method was abandoned in favor of other proximity 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. 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 an integrated circuit. The integrated circuit outputs the card number to the coil which transmits it to the reader. The transmission of the card number happens in the clear—it is not encrypted. With basic understanding of radio technology and of card formats, Wiegand proximity cards can be hacked.

A common proximity format is 26 bit Wiegand. This format uses a facility code, also called a site code. The facility code is a unique number common to all of the cards in a particular set. The idea is an organization has their 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 an 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 cards can be used to counteract the problems of transmitting card numbers in the clear and control of the card numbers by manufacturers. Smart cards can be encoded by organizations with unique numbers and the communication between card and reader can be encrypted.

• Access control
• Biometrics
• Card printer
• Common Access Card
• Computer security
• Credential
• Door security
• Electronic lock
• Fortification
• ID Card
• ID card printer
• IP video surveillance
• Keycards
• Locksmithing
• Lock picking
• Logical security
• Magnetic stripe card
• Optical turnstile
• Photo identification
• Physical Security Professional
• Proximity card
• Security
• Security engineering
• Security lighting
• Security policy
• Smart card
• Swipe card
• Wiegand effect