In this blog post, we’ll take a look at how well fingerprint and iris recognition technology on smartphones protects your privacy, and analyze the limitations and security issues of biometrics.
Today, with the development of the internet and the proliferation of smartphones, personal information is more important than ever. Mobile devices such as smartphones store sensitive information such as personal photos, messages, and financial information, and protecting it is not only a matter of personal privacy but also economic security. Therefore, security systems to protect this sensitive information from crimes such as identity theft and financial fraud are constantly evolving. Moving away from simple passwords, biometrics, which use a person’s biometric information or behavioral traits to identify them, are gradually entering our lives.
The oldest and most widespread of these biometric systems is fingerprint recognition. Fingerprints are made from the dermis of the finger, where the sweat glands protrude into the epidermis in a regular flowing line, called ridges, and the indentations are called grooves. Because fingerprints are unique to each person and remain unchanged throughout life as long as the dermis remains intact, fingerprint recognition has long been a popular biometric method, especially in law enforcement, where it has a long history of being used as a means of identifying criminals. These fingerprint recognition systems identify individuals based on the match between their enrolled fingerprints and the fingerprints that are viewed through a fingerprint input device, which reveals differences in light intensity, electrical charge, and so on along the ridges and valleys.
There are various ways to distinguish fingerprints based on these differences, including optical fingerprint recognition and capacitive sensor fingerprint recognition. The method that distinguishes fingerprints based on the intensity of reflected light is called optical fingerprint recognition. Optical fingerprint recognition was initially used in large-scale facilities, but its performance has improved in recent years, and it has been applied to various fields. Capacitive sensor fingerprinting utilizes the electrical conductivity of the skin. When a finger is placed on the input device, it detects changes in the amount of charge depending on the shape of the ridges that touch the input device to verify the identity. While optical fingerprint recognition is highly accurate, the downside is that the machines are large and expensive. Optical fingerprint recognition devices are mainly used in companies, time clocks, and banks. Capacitive sensors have the advantage of being miniaturized and inexpensive, making them easy to mass produce. However, the disadvantage is that the silicon chip (semiconductor) inside is damaged by static electricity when it is touched. Recently, however, this disadvantage has been overcome by coating the surface of the chip to increase its stability. Apple’s fingerprint recognition system, Touch ID, is also a capacitive sensor-based fingerprint recognition system. In addition to these two types, there is also the thin-film type, which uses a sensor in the form of a very thin film, and the pyroelectric type, which detects changes in temperature. As you can see, fingerprint recognition technology is evolving in various forms and has become deeply embedded in our daily lives.
Another emerging biometric is iris recognition. The iris is a doughnut-shaped membrane around the pupil that contracts and relaxes to control the amount of light entering the eye. The iris is formed around 18 months of age and remains the same throughout life. The iris has two muscles that control its contraction and relaxation: the pupillary sphincter and the extraocular muscles, which have a complex pattern that varies from person to person. The entire eye is photographed with an infrared camera that does not reflect light to extract only the iris, which is then analyzed region by region. The principle of iris recognition is to data the unique pattern of the iris. The data of the acquired iris is stored and registered, and the identity is verified by comparing it with the data of the iris being viewed.
The iris has more than 250 distinctive points, much more than a fingerprint with 40 distinctive points, so it is much more reliable and secure than a fingerprint. While traditional fingerprint recognition has a 1 in 10,000 chance of error, iris has a 1 in 1 million chance of error when using one eye and 1 in 1 trillion when using both eyes. Also, fingerprints are more visible than irises, making them harder to identify if they are damaged through hard labor or have foreign objects on them. I also have sweaty hands, which often makes fingerprint recognition difficult and uncomfortable. In addition, fingerprint recognition requires direct finger contact, while iris recognition is contactless, which is less restrictive and more hygienic. These advantages have led to the rise of iris recognition, as evidenced by the fact that smartphones from Samsung and Apple are now equipped with iris recognition technology. In the future, iris recognition technology is expected to be applied to more products and services to enhance security.
Other biometric technologies are still being developed. There’s the brainprint method, which uses the brain’s response to certain words or images to verify identity, which has the potential to lead the way for the future of biometrics. Vein recognition, a technique that recognizes the pattern of blood vessels in the fingers or wrist, is also gaining traction. These efforts to identify individuals through various aspects of their bodies are happening all over the world, and security systems are becoming increasingly sophisticated as technology advances. In the future, these biometric technologies will continue to penetrate deeper into our daily lives and set new standards for security.
