Academic Reading — Test 167

Reading passage

India's Aadhaar programme is among the largest biometric identification systems ever attempted, assigning a twelve-digit number to residents and linking that number to a set of bodily measurements. The aim is to give each person a single, verifiable identity that cannot easily be duplicated. To achieve this, the system records not only basic details such as name and address but also biometric data: ten fingerprints, scans of both irises, and a facial photograph. These physical characteristics are chosen because they remain reasonably stable over a person's lifetime and differ from one individual to the next, even between identical twins, whose fingerprint patterns and iris textures are not the same. When a resident first enrols, an operator captures their fingerprints using an optical or capacitive scanner. Rather than storing the raw image of a finger, the software identifies a set of distinctive points known as minutiae, where the ridges of the skin end or split into two. The relative positions and angles of these points are converted into a compact mathematical description called a template. Because the template is a numerical summary rather than a picture, the original fingerprint cannot be straightforwardly reconstructed from it. The same logic applies to the iris: a camera using near-infrared light photographs the coloured ring around the pupil, and an algorithm encodes the intricate pattern of folds and threads into its own template. Iris recognition is valued because the iris is protected inside the eye and changes very little after early childhood. The central task of the system is to ensure that no person is enrolled twice. This is done through a process called de-duplication. Each time a new set of biometrics arrives, it is compared against every record already held in the central database, a procedure that may involve hundreds of millions of comparisons for a single applicant. If the new templates match an existing entry closely enough, the application is rejected as a duplicate, and the person keeps their original number. This one-to-many search is computationally demanding, which is why the system relies on fingerprints and irises together: using two independent biometric traits sharply reduces the chance that two different people are wrongly judged to be the same. Once an Aadhaar number has been issued, the biometrics are used mainly for authentication rather than de-duplication. Authentication is a one-to-one check: a resident presents their number along with a fresh fingerprint or iris scan, and the system confirms whether the new sample matches the stored template for that number. The reply sent back is deliberately minimal, often little more than a "yes" or "no", so that the requesting agency does not receive a copy of the stored biometric. This design is intended to limit how much sensitive information travels across networks. Authentication underpins many everyday services, from drawing subsidised food rations to opening a bank account, where confirming identity quickly matters more than revealing personal details. No biometric system is flawless, and Aadhaar has had to confront several practical difficulties. Manual labourers and elderly residents sometimes have worn or faint fingerprints that scanners struggle to read, which can cause an authentication attempt to fail even when the person is genuine. To reduce such failures, the system allows more than one biometric to be used, so that an iris scan may succeed where a fingerprint does not. Critics have nonetheless raised concerns about privacy and about what happens when authentication wrongly denies someone a service to which they are entitled. Supporters reply that storing templates instead of raw images, and returning only a simple confirmation, are deliberate safeguards. The wider debate over how such a vast store of personal data should be governed continues, but the underlying engineering rests on a consistent idea: translating the unique texture of the body into numbers that machines can compare at enormous scale.