How does the fingerprint scanner on a smartphone: the principle of operation, advantages and disadvantages

Today, a smartphone performs not only its main purpose, it is a place to store personal, financial, and sometimes corporate information. To protect information, a reliable shield is fingerprint scanning. This is the most accurate way to identify a person’s personality, somewhat inferior to the earlier ones - retinal scanning, DNA analysis. The protrusions and depressions on the skin - papillary patterns - form a pattern that is unique to each person. Damage to the skin is not terrible - over time, the pattern will return to its original form. We will explain how one of the most reliable defenders of our information on the phone works in this article.

Operating principle

The method of obtaining a copy of the papillary pattern depends on the type of scanner that is built into the mobile device. However, any device, regardless of its type, provides the following operations - obtaining a finger pattern, checking its coincidence with a picture from an existing database. The most common are three types:

1. Optic. This reader is most often used in smartphones. The principle of operation is similar to the work of digital "soap dishes". The basis is the matrix, which consists of a photosensitive diode and an autonomous power source. If a light beam hits a photosensitive photodiode, it generates an electric charge proportional to the intensity of the stream. The result is a “picture” with areas of different illumination, which is a display of the print. If the brightness or clarity of the resulting pattern is insufficient, then a second check is performed.
2. Capacitive. They work like a touch screen. At the touch of a finger, a change in capacity occurs, which is then converted to voltage. The bulges give a certain potential difference, there is practically no depression. Based on this, an accurate pattern is formed.
3. Ultrasonic. Just like bats and dolphins orient themselves in space using echolocation, this sensor also works using sound waves. The source constantly sends pulses in the direction of the screen. The reflection of the wave from the bulge and cavity occurs in different ways - the reflection time is different. Based on this, a 3D picture is compiled, which repeats the papillary patterns of the finger. So far, such sensors are not used in mobile devices, since they are quite expensive. But work is ongoing.

If fingerprint scanning is carried out by various methods, then further processing of the information is the same. It is processed using software, its analysis is carried out, comparison / comparison of fingerprints in the database with the resulting pattern. If a complete match is obtained, then the identification is completed - entry to the device is allowed.

Advantages and disadvantages of this access method

An indisputable advantage of access from fingerprint scanning is security:

• Simplicity. Access is made with the careless movement of one finger.
• The complexity of counterfeiting or duplication compared to cards.
• The impossibility of falsification, random guessing, calculation or hacking, unlike a pin code, password.
• The inability to forget, make a mistake when entering, as often happens when entering a password.

But, as in any other, all the more reasonably new way of access, there are minuses:

• 100% reliability is in question. People who set out to gain access can use a finger phalanx cast, a fake.
• The inability to change your fingerprints during unauthorized access, as it is easy to do when changing the password, pin-code.
• So far, the encryption itself, which depends on the quality of the software and its “holes”, is doubtful.
• User authorization problems can cause injuries, cuts on fingers, dirt, screen scratches. Any, even minor, defects can make access difficult.
• Have you ever wondered how many people have used a public scanner before you? We must approach him with disinfectant wipes.

If you have trouble reading

If you can’t enter your device, then do not scold manufacturers. Maybe the thing is as follows:

• You have moisture in your hands, a coating of fat.
• There was a software failure, the device itself. Reboot required.
• You hurt, scratched your finger, it has a trace of an insect bite or another defect.

Manufacturers have provided such moments, so you can activate any device using the password or pin code. As it was said, this technology for protecting consumer-level devices is quite new. Therefore, standards and protocols will be improved as they develop, and errors will be eliminated. The adjustment accuracy will increase, encryption quality will be improved, data protection will be worked out, which will prevent data theft.