How does a fingerprint scanner work on a smartphone?

Today, a smartphone not only fulfills its main purpose, it is a place for storing personal, financial, and sometimes corporate information. Fingerprint scanning is a reliable shield for protecting information. This is the most accurate way to identify a person, somewhat inferior to the earlier ones - retinal scanning and DNA analysis. Protrusions and depressions in the skin - papillary patterns - form a pattern that is unique to each person. Damage to the skin is not scary - over time, the pattern will take on its previous appearance. How one of the most reliable protectors of our information on the phone works, we will tell you in this article.

Operating principle

The method for obtaining a copy of a 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 and checking its coincidence with a pattern from an existing database. The three most common types are:

1. Optic. This reader is most often used in smartphones. The operating principle is similar to that of digital point-and-shoot cameras. The basis is a matrix, which consists of a photosensitive diode and an autonomous power source.The impact of a light beam on a photosensitive photodiode causes the formation of an electric charge proportional to the intensity of the flux. The result is a “picture” with areas of different illumination, which is a reflection of the print. If the brightness or clarity of the resulting pattern is insufficient, then a repeat check is performed.
2. Capacitive. Works similar to a touch screen. When touched by a finger, the capacitance changes, which is then converted into voltage. Convexities give a certain potential difference, there is practically no depression. Based on this, an accurate drawing is formed.
3. Ultrasonic. Just as bats and dolphins navigate in space using echolocation, this sensor works using sound waves. The source continuously sends pulses towards the screen. The reflection of a wave from a convexity and a depression occurs in different ways - the reflection time is different. Based on this, a 3D picture is compiled that repeats the papillary patterns of the finger. So far, such sensors are not used in mobile devices because they are quite expensive. But work is underway.

If the fingerprint is scanned using different methods, then further processing of the information is the same. It is processed using software, it is analyzed, and the prints available in the database are compared with the resulting pattern. If a complete match is obtained, then identification has been completed and entry into the device is allowed.

Advantages and disadvantages of this access method

An undeniable advantage of fingerprint scanning access is security:

• Simplicity. Access is achieved with a casual movement of one finger.
• Difficult to counterfeit or duplicate compared to cards.
• Impossibility of forgery, random guessing, calculation or hacking, unlike a pin code or password.
• Inability to forget or make a mistake when entering, as often happens when entering a password.

But, as with any, especially a fairly new access method, there are some disadvantages:

• 100% reliability is in question. People who set out to gain access can use a cast of the phalanx of a finger, a fake.
• Inability to change your fingerprints during unauthorized access, as can easily be done when changing a password or pin code.
• While the encryption itself is questionable, it depends on the quality of the software and its “holes.”
• User authorization problems can cause wounds, cuts on fingers, dirt, and scratches on the screen. Any, even small, defects can make access difficult.
• Have you ever wondered how many people have used a public scanner before you? You need to approach it with disinfectant wipes.

If you have problems reading

If you can’t log into your device, then don’t blame the manufacturers. Maybe it's the following:

• There is moisture on your hands, a coating of fat.
• There was a software failure, the device itself. Reboot required.
• You have injured or scratched your finger, it has an insect bite or other defect on it.

Manufacturers have provided for such moments, so you can activate any device by entering a password or pin code. As mentioned, this technology for protecting consumer-grade devices is fairly new. Therefore, standards and protocols will be improved and errors will be eliminated as they develop.The accuracy of settings will increase, the quality of encryption will be improved, and data protection will be improved, which will prevent data theft.