How does biometric access control work?

Until a few years ago, the possibility of authenticating people through their features seemed like science fiction. However, the technology advances rapidly to the point of becoming part of our daily life, for example, the unlocking of the mobile phone through the fingerprint. But how does biometric access control work? Find out in this post.

What is biometrics

The word biometrics is composed of two words of Greek origin: bios, which means life, and metron, which is translated as a measure. It is, therefore, the science that studies the measurements of living beings or biological processes.

However, in the field of Information Technology, the word takes a more concrete meaning related to authentication. Thus, the reference "biometric access" or "biometric control" refers to those mechanisms that verify the identity of a person through their physical features or behavior.

In general terms, these parameters can be divided into two types: static (physical) characteristics and dynamic (behavioral) characteristics. The key to the analysis of these parameters is that they are unique and difficult to replicate from one person to another. Therefore, they are taken as reference for personal verification.

Aesthetic characteristics:

    Facial pattern
    Geometry of the palm of the hand
    Veins in hand

Dynamic characteristics:

    He passed

At times, the characteristics can be considered of both types, such as the voice, which is both a physical and behavioral trait.
How biometric access control works

Authentication mechanisms based on static and dynamic characteristics apply statistical and mathematical techniques. Since the nature of these parameters varies, the operation also differs. Even, the technology to measure these parameters may be different.

What all systems have in common is that they extract information from static or dynamic characteristics and compare it with the patterns they have stored in their database to verify the identity of a person.

Biometric access control applied to the business world:

    Fingerprint reader
    Access control by the palm of the hand
    Eye biometric control
    Facial recognition systems
    Speech recognition mechanisms

Fingerprint reader

As we have said, the verification translates into main steps: extract the information and compare it with the stored one. For the first of the steps, three methods of extracting the information from a fingerprint can be distinguished:

    Optical systems Its mechanism of light-sensitive diodes generates an electrical signal in response to photons. Thus, said diodes record a pixel each time the light is reflected, generating an image with light and dark. The result is a negative photo of the footprint. The image must be clear and have enough definition for a correct verification.
    Systems based on ultrasound. The mechanism sends inaudible sound signals to the human ear and picks up the different intensities it produces when hitting the different parts of the track. With this system it is possible to generate a 3D image, which offers us greater precision.

Once the system has obtained the image of the trace, verification is carried out. This is usually done through algorithms that detect the differentiating traits of the tracks (minutiae). When the system finds a sufficient number of shared features in both images, it understands that it is the same person.

Access control by the palm of the hand

Access control by geometric verification of the palm of the hand is one of the most widespread systems of biometric access.

For geometric authentication, a front and side image of the palm of the hand is extracted with a digital camera. From there, the system performs a series of measurements such as:

    Width and height of the palm of the hand
    Width and height of the fingers
    Angles of union of fingers and palm
    Deviation of the phalanges with respect to the right angle that should form