However, ease and speed of use are also important factors, as slow, difficult and unreliable systems may become misused and ineffective. So it is important to get the right balance between security and ease of use. Technologies range from inexpensive, low security keypads, to high security proximity cards and sophisticated biometric systems.
The following is a very simplistic guide to the relative security of the different technologies showing the decreasing levels of security:
- Biometric – Impossible to replicate
- Proximity
- Watermark
- Wiegand
- Smart Cards
- Infra-red
- Magstripe
- Barcode
- Keypad PIN only – very easy to replicate.
Biometric systems use physical attributes such as fingerprints, retina scans and voice recognition for identification. The sensitivity of most biometric products must be carefully adjusted. If the sensitivity is set too high, a user may need to try several times before their identification is accepted. If the sensitivity is set too low, it is probable that an unauthorised user could gain access.
Proximity reader is the most popular form of ID device. The user simply presents the key or card to the reader in order to release the door.
No actual contact is made between the ID device and the reader, so wear and tear is avoided. Proximity readers are renowned for their ease of use and reliability. Because there are no slots or holes to be damaged, they are also highly resistant to vandalism and adverse weather. Typical reading distances are between 0 and 5cm.
Reading range: If a keyfob ID device is used, it must be presented within 5-20cm (range is dependent on the reader and type of ID used) of the reader. If the ID is valid for that door, the red LED will turn to green and the door will unlock. ID cards generally have a reading range up to 20% longer than keyfobs. The reading range of any ID device depends on which reader it is used with. (For example, the range can vary from 1-2cm on a PAC Vandal Resistant Reader, up to 25cm on the PAC range of readers.) Other manufacturers may quote much longer reading ranges, but these are often achieved with active ID devices that require batteries and have a limited life span.
PAC ID devices are passive. This means that they do not require any batteries, but gain their power from a coil in the reader head which induces a current in the coil of the ID device when it comes within range of the reader.
PAC readers can often be concealed by wood, glass or plastic as the ID device can still be read through any non-metallic material. This makes for a better installation and further reduces the risk of vandalism. However, it is vital to make sure the reader has enough range to cope with the extra distance to the ID device.
Customising cards: The card can be printed onto directly, or laminated so that company logos and photographs of card holders can be incorporated. However, the manufacturer should be consulted before printing onto ID cards because the printing process to be used may affect the type of ID card required. The cards can also have slots punched in them and a number of ID card accessories are available that allow the cards to be worn and displayed in different ways.
High security: PAC ID cards and tokens are high security devices. Each device is programmed with its own unique code. It is impossible to reproduce these devices without going to a specialist manufacturer.
Hands free: Like proximity, hands-free technology requires no contact between the ID device and the reader. However, the reading distances are much greater, typically up to 70cm, so that the door unlocks as the person approaches. Although the typical reading range is 70cm, it can vary between 10cm and several metres. The longer range devices use active ID devices which means they usually have an internal battery to boost the signal.
The reader electronics are hidden away and attached to a large wire loop which can be hidden behind a door frame or in the roof or floor. This type of reader is very sensitive to interference from PC monitors and other electro-magnetic devices. The positioning of these long range readers can be critical and a site survey by the manufacturer is strongly recommended.
The watermark card uses an encoded strip of film which is placed onto a card. However, it is far more secure than the magnetic stripe because it is securely coded and is more difficult to copy.
Wiegand cards are manufactured with a wiegand ribbon or tape. This tape has short wires embedded in to it, which are individually polarised giving a code when passed through a magnetic sensor. Wiegand cards are highly durable and long lasting. However, the card readers use the same design as magstripe readers, so they are not suitable for harsh conditions as the exposed reader heads can become damaged.
Like proximity, smartcards have a chip which stores information. The significant difference is that you can write information onto a smartcard. This makes them ideal for additional uses such as electronic purses or library cards.
There are two types of smart card: contact and non contact. Contact cards are seen as more secure. especially by the banking sector, as the data is transferred to and from the reader by making physical contact with the card. This is in contrast to the non contact cards which transmit the data. It is the fear that this transmission of data over the airways may be picked up by an unauthorised third party. Contact cards have a much higher memory capacity.
Non-contact cards are seen as more reliable in terms of longevity as the readers have no moving parts. This is in contrast to contact card readers which are motorised and have slots which could be vandalised. Smart card manufacturers are developing dual contact and non contact cards. These dual cards will give the best of both worlds, solving the security concerns of the banking sector while offering great reliability for high usage applications.
Infrared ID devices are active with a built-in battery. The device is operated by pointing it at the reader with its button pressed. This gives a long reading range of up to 9m, and is ideally suited for applications such as car park barriers, where a driver could operate it from inside the car. Unfortunately, this technology can be affected by bright sunshine.
The Magstripe card uses an encoded magnetic stripe laminated onto a PVC card. This is one of the most widely used technologies due to the low cost of both cards and readers. However, magstripe readers are not suitable for harsh conditions as the exposed reader heads can be damaged. Magstripe cards can also become corrupted, worn out or bent and are easy to duplicate, so they are not suitable for high security applications. To use the card, the user swipes the card through the reader next to the door in a downward direction.
Unlike the familiar supermarket type barcodes, the barcode widely used in access control applications is invisible and read by an infra-red reading head. These cards are inexpensive, but they are simple to duplicate.
Source
Security Installer
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