1 June 2012
Last updated at 03:35
For the past two years the Indian government has been creating the world's largest and most sophisticated database of personal identities. Photographers Mansi Thapliyal, Shailesh Andrade and Gitartha Goswami have been documenting the exercise.
Since the scheme launched, 200 million Indians have already signed up for a 'unique identity' (UID). By 2014, another 400 million people are expected to have enrolled, fulfilling the scheme's mandate to cover about half of India's people.
Giving Indians a definitive, portable identity is also turning out to be the world's largest biometric exercise - thousands of enrolment centres have been set up across the country to record the data.
The details of the person are fed into a computer before they are photographed and their fingerprints and iris scanned. Millions of Indians lack what identity scheme chief Nandan Nilekani calls "any form of acknowledged existence", which essentially ends up depriving them of their rights and pushes them into a faceless existence.
The identity number promises to be a secure proof of identity for India's residents from "birth to death", as one official says. The number will help people to secure welfare benefits, pay pensions, receive salaries, obtain cooking gas and mobile phone connections, among other things.
But the scheme has its critics who have raised concerns about access to and misuse of personal information, the risks of surveillance, profiling and how secure confidential information held by the government will be.
Authorities say that appropriate steps have been taken to ensure security and protection of data.
There are also concerns about people not being sufficiently informed about the potential consequences of having an ID number before they sign up for one. Many people the BBC spoke to at enrolment centres said they were there because their friends had told them it "was a good thing".
The poorest of the poor are expected to benefit most from the UID. Even though many of them have some form of ID, such as a voters identity card, most have no proper papers and therefore no access to services such as subsidised food rations, a phone connection, even a bank account.
Many see their new 12-digit number, also called Aadhaar (Foundation), as a potential game-changer, bringing the poorest into the mainstream, reducing waste while ensuring federal welfare money reaches those who need it most.