The total cost of allocating unique identification numbers to the 1.2 billion population in the country may not cross Rs 18,000 crore, Aadhaar Project Mission Director Ram Sewak Sharma today said.

"... The de-duplication work has been brought down to just Rs 2.75 per person and the entire outsourcing work will cost Rs 50 per citizen. The total cost may run up to Rs 150 per person which amounts to Rs 18,000 crore...," the UIDAI director general told reporters here.

The Parliamentary Standing Committee on UIDAI raised serious questions about the idea of Aadhaar itself fearing that the project would ultimately cost the nation a fortune.

It demanded a re-look at the foundational principles on which the project was conceived.

It had said that the project raises serious questions about the enrolment process which was riddled with "serious lacunae".

The UID can cut down pilferage of subsidies provided to the citizens, Sharma said, adding the Centre provided Rs 3 lakh crore of subsidies every year.

UIDAI Chairman Nandan Nilekani, who was also present in the press conference, however, played safe by saying that the committee report was being analysed by the Union government which would take a suitable decision.

To a question he said this report would not hamper the project nor slow it down. "We will be approaching 200 million mark by this month end of first week of February. We are enrolling nearly one million people every year."

However, he said the authority would not be in a position to filter foreign nationals residing illegally in India.

When asked about the National Population Registry advocated by Union Home Minister P Chidambaram, Nilekani said there was a 'group' which wanted its merger with UID project, but the Union Cabinet would take a final decision.

UIDAI Technology Head Srikanth Nadhamuni said the authority had ensured extensive use of encryption to safeguard the data collected.

"We have designed extremely sophisticated software, Biometrics, fraud detection systems and data mining at the back end... We also follow due protocols and processes for data security and protection," Nandhamuni said, allaying fears of misusing of personal details listed in Aadhaar Unique Identification numbers.

UIDAI Chief Architect Pramod Varma said the data centres had a seamless physical as well as digital security systems in place at the city and Greater Noida facilities and was a 'extremely secured zone'.

He said UIDAI had employed 'logical security' by petitioning data centre into zones separating them using firewall and network intrusion detection and prevention system.

"Every enrolment data packet is always stored in Public Key Infrastructure encrypted, tamper proof files and are never decrypted or modified during transit until it reaches UIDAI's data centres," he said.