The head of the census has promised Australians their personal data will be subject to the highest security as several politicians refuse to provide their names and addresses citing privacy concerns.

All Australian households are required to complete the five-yearly national snapshot on Tuesday night but politicians including independent Senator Nick Xenophon say they’ll risk a fine.

Census head Duncan Young has moved to assure people their information will be stored internally and not end up on the web.

“Hand on heart, the security set-up in order for people to submit their information – it’s encrypted all the way through from their browsers into the ABS’s internal environment,” he told the Nine Network on Tuesday.

“Then we go through the process of separation. The information is isolated so people who can access names can’t access the rest.”

Nick Xenophon says he will withhold his name from the census. Photo: Getty

People have given the Australian Bureau of Statistics their names and addresses since 1911 – but the information will now be kept for four years instead of 18 months.

Senator Xenophon says people might lie on the census because of concerns their information could be misused.

“Rather than be a snapshot of the nation, this census will morph into a mobile CCTV that follows every Australian,” he said.

Greens Senators Scott Ludlam and Sarah-Hanson Young also say they will withhold their names.