The card (RFID)
Fast and practical for large numbers, hygienic (no touch), and easy to cancel if lost. Its weakness is that it identifies the card, not the person — it can be lent or stolen. It suits offices and busy facilities where speed matters more than absolute certainty of identity.
The fingerprint
Ties entry to the person rather than to something they carry, at a reasonable cost. Its weaknesses: it is affected by dirty, wet or cut hands, it is a little slower in a queue, and there is the matter of shared touch. It suits medium facilities and sensitive doors.
Face recognition
Fast and touch-free (hygienic), ties entry to the person, and works even when hands are full. It needs suitable lighting and a good device to avoid errors, and it is usually the most expensive. It suits main entrances and sites where speed, hygiene and identity all matter.
The PIN
The cheapest and simplest, but the weakest: a code is shared and can be stolen by watching. It is rarely used alone on an important door; its real value is as a second layer above another method.
Combining two methods
For highly sensitive doors (safes, server rooms, restricted stores) more than one method is combined: card plus fingerprint, or face plus PIN. This raises security considerably, because defeating two methods together is far harder. Ordinary doors are served by one suitable method.
How to choose
- Heavy traffic and speed: card, or face if you want identity tied in.
- Certain tie to the person: fingerprint or face.
- A highly sensitive door: two methods together.
- A dirty environment or full hands: face suits better than fingerprint.
