5 Reasons Why Fingerprint Scanners Are Not Good in Securing Smartphones


By Frettie (Own work) [GFDL ( or CC-BY-3.0 (], via Wikimedia Commons

Fingerprint scanners in mobile devices are nothing new. They have been used in some Motorola handsets before. However, after getting reintroduced in the iPhone 5S, fingerprint scanners appear to be one of the new features smartphone manufacturers are trying to add as a supposedly attractive new feature. Does this make sense? Is your fingerprint really a good way to control access to your devices?

How Fingerprint Scanners Work

Because fingerprints are unique to every person, proponents of fingerprint scanners believe that they serve as an effective way of limiting access to devices to the person who owns the specific fingerprints. Fingerprints are also inseparable from their owners so there is no problem of forgetting or misplacing them. Those who want to access their fingerprint-locked devices can simply swipe or press their fingers on the scanner.

Fingerprint scanners work in various ways, the ultimate goal of which is to match a fingerprint to the print or pattern stored in the scanners. The fingerprint recognition process may be through optical, ultrasonic, and passive or active capacitance. Also, there are two main ways of having a fingerprint scanned: by sliding or by pressing the fingers over the sensor.

By D. Sharon Pruitt (Originally uploaded on flickr by D. Sharon Pruitt) [CC-BY-2.0 (], via Wikimedia Commons

By D. Sharon Pruitt (Originally uploaded on flickr by D. Sharon Pruitt) [CC-BY-2.0 (], via Wikimedia Commons

Reasons Why Fingerprint Scanners Don’t Mean Excellent Security

At least when it comes to ordinary folks, fingerprint scanners are not a very sensible option in protecting access to devices. They are no better than the standard passwords or pattern locks used at present. It can be argued that they don’t really improve device security and that they are only adding to the cost of already expensive devices. The Youtube video on this link can summarize the shortcomings of fingerprint scanners.

1. It is not difficult to obtain fingerprints.

If your fingerprint is your key to your fingerprint-scanner-toting device, you are practically leaving your key on almost everything you touch. Think about it – the smudge you leave on a drinking glass or on other smooth surfaces can be scanned to get your fingerprint pattern. You can easily obtain fingerprints using high resolution cameras which are widely available at present.

2. The sensor can be tricked.

I, NobbiP [GFDL (, CC-BY-SA-3.0 ( or CC-BY-SA-2.5-2.0-1.0 (], via Wikimedia Commons

I, NobbiP [GFDL (, CC-BY-SA-3.0 ( or CC-BY-SA-2.5-2.0-1.0 (], via Wikimedia Commons

Because smartphones are mobile or very portable devices, trying various ways to try to get through the fingerprint protection security is unconstrained. It’s just like trying to crack a password or pattern lock protection — maybe even easier.

A group called Chaos Computer Club showed a not-so-complicated method to trick the iPhone 5S fingerprint sensor. It did not even involve any special or advanced technology. Almost anyone can do it. All it takes is a high resolution photo of the fingerprint, a high resolution printer, and a fastener.

Some sensors require a heat signature or pulse on the finger being scanned to avoid instances when fingers are merely being simulated with the help of 3D printing technology. Still, this heat signature and pulse requirement is not difficult to bypass. A fingerprint pattern printed on a skin colored material can easily trick the sensor.

3. It’s easier to force you to use your finger to unlock your phone than to make you speak out your password or force you to use the unlock pattern.

It’s not difficult to realize that those who really want to unlock your fingerprint-locked smartphone can simply grab your hand and forcibly use it to unlock the device. Compared to password and pattern locks, this is way easier to do. It can also be done while you are asleep or unconscious.

4. Sometimes they work, sometimes they don’t.

There have been reports of users having problems with the fingerprint scanners on their iPhone 5S. It’s similar to the problems encountered with the earlier mobile devices that support fingerprint recognition and unlocking. Apparently, the technology is still not that mature to be able to integrate a fully reliable biometrics-scanning module in a thin and light mobile device like the iPhone 5S.

A  number of factors affect the functioning of these sensors. These include moisture on the fingers, dirt, the integrity of the software behind the sensor, as well as possible damages in the glass covering the sensor. In the case of Apple’s iPhone 5S, the culprit is believed to be the software. For the latest Samsung device, on the other hand, demonstrations show that it may take a few more swipes to finally get the fingerprint sensor to detect the fingerprint.

5. Some companies just don’t know how to implement fingerprint reading security properly.

Fingerprint sensors on smartphones are not really a complete failure. It’s just that some manufacturers only add them for the bragging rights and to attract gullible customers. The fingerprint scanner on HTC One Max, for example, is very difficult or inconvenient to use, just like the way it was in devices from the past.

I, Avenafatua [GFDL (, CC-BY-SA-3.0 ( or CC-BY-SA-2.5 (], via Wikimedia Commons

I, Avenafatua [GFDL (, CC-BY-SA-3.0 ( or CC-BY-SA-2.5 (], via Wikimedia Commons

It would be backward-thinking to insist that fingerprint scanners on smartphones are completely useless. Of course, they do have uses and vast potential. It’s the implementation that has the say on whether or not these fingerprint scanners become useful or worthless. Basically, the best thing that can be done for now is to make fingerprint scanning only as a complementary security method. When paired with a traditional password or pattern lock, fingerprint scanners can considerably improve device security.