biometrics

biometrics, measures of individuals’ unique physical characteristics or behavioral traits that are typically used in automated recognition technology to verify personal identity. Physical characteristics used include fingerprints, faces, retinas, and voice patterns. Biometric authentication may be used to manage an individual’s access to resources such as buildings, rooms, computers, and phones.

History

Automated biometric systems did not become popular until the 1990s, but the ideas on which they are based originated thousands of years ago. Ancient Egyptians identified trustworthy traders by their physical descriptions. In Babylon fingerprints were used as identification by merchants who recorded business transactions on clay tablets dating back to 500 bce. Chinese merchants also used fingerprints as identifiers for business transactions, in the 14th century.

Official biometric classification systems for security purposes began to appear in the late 1870s and early 1880s. In 1879 Paris police officer Alphonse Bertillon developed and introduced an identification system known as Bertillonage, or “signaletics,” which identified people by head and body measurements as well as by the shape of their ears, eyes, eyebrows, and mouth. The system also accounted for tattoos, scars, and personality traits. The information was recorded on cards that included photographs of individuals’ front and side profiles. The Parisian police force adopted the system in the early 1880s.

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In 1892 British scientist Frances Galton published a book about a fingerprint classification system he had developed based on three main pattern types: loops, whorls, and arches. Although his initial purpose was to identify distinctions in fingerprints between different races (reasoning that did not hold up to experimentation), his system showed that no two people’s fingerprints are the same and that fingerprints remain the same throughout a person’s life. Four years later, after consulting Galton, Edward Henry, inspector general of the Bengal Police of India, implemented the fingerprinting system. His assistant Khan Bahadur Qazi Azizul Haque developed a mathematical formula to classify fingerprints. The Henry Classification System, as it came to be known, laid the groundwork for systems that would be used by the Federal Bureau of Investigation (FBI) and other law enforcement organizations for many years. The Henry system effectively replaced the Bertillon system in the early 1900s.

New York state prisons began using fingerprints for identifying people released from their custody in 1903, after which several other states and law enforcement agencies established their own fingerprinting systems. In 1924 the FBI established an identification division to serve as a national repository and clearinghouse for fingerprint records.

Over the next several decades more biometric technologies were developed. Some notable advancements include the semiautomation of facial recognition, developed by Woodrow (“Woody”) Bledsoe in the 1960s; speech recognition systems funded by the U.S. Department of Defense in the 1970s; a hand-geometry recognition system devised by David Sidlauskas in 1985; vascular pattern recognition developed by Joseph Rice in 1985; and an iris recognition system devised by John Daugman in 1994.

Types of biometric systems

Physiological biometrics are based on relatively fixed individual features, such as facial contours, fingerprints, iris patterns, and vein geometry. Systems that use physiological biometrics include fingerprint scanners, facial recognition, ear authentication, and retina scanners.

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Behavioral biometrics, on the other hand, rely on an individual’s characteristic voluntary and involuntary movements and gestures. Examples include typing rhythm, walking, and voice, which correspond to the biometric methods known as keystroke recognition, gait analysis, and voice recognition.

Biometric authentication systems rely on three components: a scanning device or reader that captures an individual’s data, a database with stored information, and software that processes the individual’s data and searches the database for a match.

Modes of operation

Biometric systems have two different modes. Verification mode confirms an individual’s identity by a one-to-one comparison of the individual’s captured data with existing data about that individual found in a system database. Identification mode identifies an unnamed individual by performing a one-to-many comparison of the individual’s captured data to find a match in a system database.

Systems are also differentiated based on how many markers they use. Unimodal authentication systems capture and analyze biometric data from a single biometric marker (e.g., a retina scan), while multimodal authentication systems capture and analyze biometric data from two or more identifiers (e.g., a retina scan combined with voice recognition), making it more difficult for bad actors to access private information.

Privacy

The use of biometrics has raised concerns about privacy infringement. Biometrics can be used to access personal data for purposes other than those for which it was originally collected for (called function creep), or to collect personal data without an individual’s knowledge or consent. Well-designed biometric systems aim to provide convenience and can protect individuals from unauthorized parties who might seek to steal their identities.

When using biometric data to protect a user’s privacy, there is always the chance that the data may be compromised. For example, in 2018 the largest ID database in the world, Aadhaar, was hacked by malicious actors who collected users’ fingerprints and iris scans, among other personal information. In a case that traversed multiple sectors, the biometrics system Biostar 2’s data was breached in 2019. The system, created by the security firm Suprema, was used by both the police and banking industries. Such breaches highlight the risks of using biometric technology as a security measure. For example, breaches could expose whether someone had accessed a certain type of healthcare or attended a confidential meeting. Biometric data may even be attained from users’ social media profiles. Makeup tutorials and the like reveal influencers’ eye shapes, ear shapes, and voices, among other data. Such information can be scraped for nefarious purposes, such as creating deepfakes or accessing accounts through voice recognition.

Common uses

In banking and credit card processing, biometric systems are used to manage customer and employee identities to help combat fraud and increase transaction security. In an industry where passwords and pins are often insufficient to prevent hacking and security leaks, biometrics add a layer of security to the process. This is especially true with behavioral biometrics, which can alert banks to unusual customer activity based on the speed at which they respond to an alert or the manner in which they enter their password.

Hospitals use biometric systems to create digital profiles of patients, complete with their medical histories, in order to accurately track each patient, identify patients in an emergency, and make sure the right patient gets the right care. The technology can also be used for newer applications, such as prescribing medication remotely.

In travel, airports use biometric systems to rapidly identify passengers through real-time screenings for a smoother airport experience. Electronic passports (e-passports) that store biometric data are also available.

Apple introduced the Face ID feature on iPhones starting with the iPhone X in 2017. The system replaced the previous fingerprint Touch ID feature, which had been introduced with the iPhone 5S in 2013. Face ID places tiny dots onto users’ facial contours to create a map of their features. It also captures an infrared image of users’ faces. The system then compares the captured image with the existing facial mapping stored on the phone, which allows a user to unlock the phone. (Facial mapping information is not stored remotely on the cloud.) Face ID, which Apple states is more secure than Touch ID, appears on iPhones and the iPad Pro.