Mobile fingerprint scanners have become integral to every smartphone. manufacturers claim that the biometric sensors improve both user experience and security of mobile devices. But is that a valid claim? dheeraj jangra finds out...
The use of fingerprints as unique identification devices can be traced back to centuries. In ancient Babylon, it was a norm to press fingertips into clay to seal business transactions. The Chinese used ink-on-paper finger impressions for business and to help identify their children. By the end of the 19th century they were regularly being used in criminal investigations. The smartphone fingerprint scanner technology made its debut in 2011. Motorola’s Mobility Atrix 4G was the first mobile phone with a fingerprint scanner. But it was not until the release of iPhone 5s (in 2013) that the technology started making waves. Now smartphones costing less than Rs 10,000 boast of snappy fingerprint scanners. It’s clear that the days of the hard-to-recall password are numbered. According to market research firm IHS, the number of fingerprint sensors embedded in devices will grow from 499 million in 2015 to 1.6 billion units in 2020. But how safe are they?
The fingerprint sensors — in addition to conveniently unlocking a screen — have also been used for authentication in mobile wallets and banking features. If your password is leaked, you can easily come up with a new one. But fingerprints are your identity, and once they are stolen, there is little you can do.
This year, a study by researchers at Michigan State University found that fingerprint scanners can be fooled by simple objects like inkjet printers. The researchers said they utilised an inkjet printer and a special photo paper to replicate fingerprints and unlock devices (Samsung Galaxy S6, Huawei Honor 7) in just 15 minutes! On an iPhone, the researchers were able to get “mixed results”. According to the team, the aim of this study is to show how weak the current fingerprint reliant systems are. However, the proposed software may prove ineffective on the upcoming models. But it’s only a matter of time before hackers devise ways to not only get past fingerprints but other biometric traits as well that are being adopted for mobile phones (e.g., face, iris and voice).
Fingerprint scanner variants and how they work
Optical scanner
An optical scanner functions by shining a bright light over your fingerprint, taking what is effectively a digital photograph. The scanner uses a light-sensitive chip called CCD (charge coupled device) to produce a digital image. The image captured has a higher contrast than the one taken by a regular camera. When your finger is placed over the scanner the resultant image is dark, so an optical scanner uses LEDs as a flash to brighten the picture during scan. The scanner then compares the captured fingerprint with the one that is stored in the data. However, the bulky design of an optical scanner can’t be implemented on a smartphone. It’s usually put to use in office attendance biometric systems, Aadhar card registrations, etc. The biggest drawback with optical scanners is that they are easy to mislead.
Capacitive scanners
Like optical scanners, capacitive fingerprint scanners generate an image of the ridges and valleys that make up a fingerprint. The only aspect which differs is that optical scanners use light for sensing, while capacitive scanners use electric current. The scanner measures the depth between the ridges and valleys to build a picture of your print. The image is converted to a code and becomes your template. This is the most commonly used fingerprint scanner, but it is not foolproof.
Ultrasonic scanners
This is the latest technology in the world of smartphones. Developed by the San Diego chipmaker Qualcomm, this fingerprint scanning technology is called Sense ID. It creates a 3D model of your fingerprint using ultrasonic sound waves. When the finger is placed on the scanner, an ultrasonic pulse is transmitted, where some of the pulse is absorbed, while others bounce back to the sensor resulting in a highly detailed 3D map of the finger. Here too, you get extremely detailed data about every ridge and valley that’s unique to your finger. It can also read through moisture or grime, so you don’t have to wipe your hands before unlocking your phone. This technology was first used on Le Max Pro smartphone.
Tips to keep in mind while using a fingerprint scanner
The index problem
Most users are accustomed to using the index finger or thumb as their biometric login. But these are the fingers we use the most while using a phone. As you know, the slippery and glossy surface of smartphones attracts fingerprints. Lose your device and a hacker could probably find enough of a print somewhere on the device to reconstruct it. So it’s better to use the little and ring finger on the left hand for right-handers and vice versa for biometric login.
Banking transactions
Mobile payment services such as Android Pay, Apple Pay and Samsung Pay are proliferating at a rapid pace. In the times to come, most of our banking transactions will be completed by fingerprint authentication. But this is not safe. In case your phone gets stolen, the hacker can copy your fingerprints from the phone surface to commit a fraud. Hence, opting for a unique password is advisable. But make sure you create a strong password with a mix of numbers, alphabets and symbols.
Second line of defence
Afingerprint scanner is not enough to protect your personal data. If you care about privacy, there are multiple apps (Lookout, Cerberus, Prey, Android Lost, etc) that offer a wide range of options for finding or protecting your device: GPS location, sounding an alarm, locking the phone, wiping the data, and more. In general, the fingerprint scanner is a great innovation. But we have to use it wisely – choose strong passwords, two-factor authentication and apply other security measures.