What Face ID is
Face ID is recognising a person from an image of their face. In an attendance system it takes the form of a terminal at the entrance: the employee steps up to it, the camera reads their face, the system matches it to an employee in the database and writes down the arrival time.
The whole thing takes a few seconds. The employee touches nothing, carries no card and types no password.
How it works technically
There is a common misconception here: people assume the system stores a photo and compares pictures each time. That is not what happens.
During enrolment the device measures geometric features of the face: the distance between the eyes, the proportions of the nose and jaw lines, and other points. Those measurements become a digital template. On each later arrival a fresh measurement is compared against that template.
You cannot reconstruct a face from the template. What is stored is not a photograph, it is a set of numbers.
How it differs from cards and fingerprints
In a card system the record goes through the card, which means the system recognises the card and not the person. A card can be handed to a colleague, and in practice that happens often.
A fingerprint solves that but introduces something else. It requires touching a scanner, which is a problem wherever hygiene requirements are strict. On top of that, in manufacturing and construction the scanner will not read a hand that is dirty or damaged.
Face ID, unlike either, needs no contact and cannot be handed to someone else.
Data security
Biometrics deserve extra care, because a password can be replaced and a face cannot.
Three things matter in practice. First, the template must be stored encrypted. Second, access to it must be limited by role. Third, every action must land in a log, so it is visible who changed what and when.
Telling staff in advance belongs on the same list. What is collected and what it is used for should be written into internal policy.
What installation needs
The terminal goes at the entrance, where people already walk. Two things matter: light and height.
The device should not face direct sunlight, or the camera may read faces incorrectly. Height is chosen for average build, usually between 140 and 160 centimetres.
Each employee enrols once. That takes a few seconds, and a whole team is usually done inside a day.
Know the limits
Every technology has a boundary and it is better to know it in advance.
Face ID is built for a fixed workplace. A sales rep or a courier never walks past the terminal, so they need a geofenced mobile app instead.
OneWork works with Hikvision terminals today. We do not promise support for other manufacturers' devices, because that would not be true yet.
In short
- The terminal stores a numeric template, not a photograph
- Face ID cannot be handed to a colleague
- No contact is required, which matters where hygiene does
- Lighting and mounting height affect accuracy
- Mobile staff need a geofenced app, not a terminal