Discovery Science: Technology – Biometric Techniques

Physics and Technology – Technology – Biometric Techniques

Biometric techniques focus on an individual’s physical traits or behavioral patterns, instead of using a PIN code, password, magnetic card, or key. This allows for a quicker and more
secure verification of people’s identities.

Biometric techniques are largely free from disadvantages such as forgotten or stolen passwords or lost keys. Physical characteristics used by biometric systems include fingerprints and geometry of the face, iris, or hand. Behavior-based identifiers include signatures, voices, and key- stroke patterns. Personal traits can change over time, however, especially those related to behavior.

A person’s individual data is first entered into the biometric system in a process called enrollment: for example, a fingerprint scan or a photograph of his or her face. Depending on the system used, a data set or template is produced from these raw data, using special mathematical procedures. This template can be stored in the individual’s personal ID card or passport or in a database, along with their identifying information to be accessed as needed.

An individual’s identity may be checked, for example, during an access-control procedure. The physical traits are captured again. If the two match, the system registers that the person’s identity has been recognized.

Secure operation

Biometric systems are subject to minor or major errors in recognition, due to traits changing over time, such as age, illness, or the presence of foreign sub stances such as dirt. Errors can also arise, for example, from changes in hairstyles, contact lenses or when fingers are placed differently on the scanner. To compensate, traits are not expected to match exactly but just to display an adequate degree of similarity.

Some biometric characteristics may be better suited to particular applications. Care must be taken that a biometric system does not accept counterfeited fingerprints or severed fingers. Due to cost reasons, techniques available to prevent this are more likely to be used only in high-security applications.

In addition, several biometric systems may be combined, or they may be monitored on-site by security personnel.


In many computer systems, fingerprints are used to authorize individual users. Registered customers of some businesses can pay with the touch of a finger. The fingerprints of criminal suspects are compared by computer with prints left at the crime scene.

Internal gates to control entry into critical areas—for instance, in a nuclear power plant—are monitored by various biometric systems as well as security personnel. Some nations’ passports have embedded radio-read- able RFID chips that store biometric data.