Mobile phones are more than just communication devices. They are also storage units for valuable business and personal data, as well as means of payment. The physical loss of a mobile phone, however, can be mitigated by the existence of advanced security options which make the device unusable by any unauthorized person.

Security in mobile authentication has evolved tremendously in the last few years. PIN numbers and passwords are being replaced at a steady pace by biometric authentication.

What is Biometric Authentication and How Does it Work?

Biometric authentication requires the phone owner to submit a uniquely patterned part of their body, such as the fingerprint or the iris to analysis and comparison to a master image. The technology used for biometric authentication involves infrared rays, which present a safe and non-invasive method of highly detailed analysis of the item.

Biometric authentication is not a new concept—it has been in use for years by companies to allow their employees’ access to the premises or to secure and sensitive areas in the office building, where only authorized personnel may enter.

The challenge was to miniaturize these devices enough so they could fit inside a mobile phone. This was a serious challenge, indeed, because the general design trend for smartphones is to make them as thin as possible.

Types of Biometric Authentication Used in Mobile Phones

1. Fingerprint Recognition

The first phone that included a fingerprint sensor was Motorola Atrix in 2011. However, that model used an optical sensor, which did not guarantee a highly reliable identification. The first phone model to feature a capacitive fingerprint scanner was Apple’s iPhone 5S. Vivo’s smartphone X21, released earlier this year, even features in-display fingerprint scanning with the fingerprint pad embedded in the screen.


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Vivo X21 | Source: Vivo

There are a few issues with fingerprint identification. For one, if the phone is placed inside a protective case, the fingerprint sensor may be inaccessible or make an inaccurate reading. Also, studies have shown that it is possible to trick a fingerprint sensor with faux fingerprints.

2. Face Recognition

Apple’s iPhone X offers users a new way to unlock their phones: by letting their faces be scanned by the front camera. The Face ID feature of the milestone Apple model is extremely advanced, because it makes a 3D analysis of the owner’s face. Thus, using a photo will not trick the phone into granting access.

Apple’s 3D face recognition system uses more than 30,000 dots to compare the facial image against the master image stored in the phone memory. Thus, the phone owner will be able to unlock their phone even if they change their hairstyle, wear a hat, glasses or grow a beard.


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Face ID, iPhone X | Source: Apple

3. Voice Recognition

A person’s voice is as unique as their fingerprint. It has specific inflections and vibrations, which cannot be reproduced by another person, no matter how hard they try to mimic them. Specialized software can analyze a speech sample and compare it against a master recording, using criteria such as pronunciation, voice wave type, speaking speed, pitch and accent.

This form of authentication is available for Android phones starting with Android Lollipop operating system models. Recently, LG Electronics created its own patented voice recognition service for unlocking its mobile phones. This feature is available for LG smartphones starting with the V30 model.


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LG V30, Voice recognition | Source: LG

4. Iris Recognition

The iris of the human eye has an extremely complex structure, which is unique for every person. Iris scanners have been introduced to the world of mobile phones starting with the Samsung Galaxy S8 model.


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Galaxy S8, Iris scan | Source: LG

A few other Android phone models incorporate this type of biometric authentication, including the latest range of Samsung flagships, Alcatel Idol 3, ZTE Grand Z3 and Vivo X5Pro.

A video shared by a group of hackers in Germany allegedly shows how they tricked the Samsung Galaxy S8 iris scanner by using a dummy eye. However, no other similar attempts were made public for this or any other smartphone models using iris identification.