New Delhi: Aadhaar is a 12 digit unique-identity number issued to all Indian residents based on their biometric and demographic data.

The data is collected by the Unique Identification Authority of India (UIDAI), a statutory authority established on July 12, 2016 by the Government of India, under the provisions of the Aadhaar Act 2016.

Aadhaar is the world’s largest biometric ID system, with over 1.13 billion enrolled members as of March 31, 2017.

It, however, is not a proof of citizenship, and does not itself grant any rights to domicile in India.

World Bank Chief Economist Paul Romer recently described Aadhar as “the most sophisticated ID programme in world”.

On March 11, 2016, the Aadhaar (Targeted Delivery of Financial and Other Subsidies, Benefits and Services) Act, 2016 was passed in the Lok Sabha (Lower House of Parliament). The Act received the assent of the President on March 25, 2016 and came into force on September 12, 2016. Before the enactment of the Act, UIDAI functioned as an attached office of Planning Commission since January 28, 2009. On March 3, 2016, a Money Bill was introduced in the Parliament to give legislative backing to Aadhaar.

The Act makes Aadhaar number necessary for certain subsidies, benefits and services, the expenditure for which is incurred from the Consolidated Fund of India.

The Modi government had pitched the Aadhaar law passed by Parliament last year to plug leakages in delivery of subsidies and government services.

It was aimed at circumventing a Supreme Court directive that allowed the government to require people to submit their Aadhaar numbers for a handful of services such as gas subsidy. Last year’s law, however, gave the government a free hand.