The federal government has introduced its controversial data retention draft laws into parliament.
Communications Minister Malcolm Turnbull said the legislation would give national security agencies greater investigative powers, requiring telcos to keep a "limited set of data" for two years.
It would capture metadata - information about communications - but not the content.
"(Metadata) plays a central role in almost every counter-terrorism, espionage and organised crime investigation," Mr Turnbull told the lower house on Thursday.
He stressed access to content would require a warrant.
The government recognised that data retention raised genuine concerns about privacy, the minister said.
But the powers under the legislation were not new - it would simply ensure that data would continue to be available to security agencies as part of "legitimate" investigations.
A person's web browsing history would not be captured, nor would service providers be allowed to keep detailed records tracking a person's movements.
Mr Turnbull said the powers were needed because of the terrorism threat level.
"No responsible government can sit by while those who protect our community lose access to the tools they need to do their job," he said.
"In the current threat environment, we cannot let this problem become worse."
The government will release the draft data set and refer it with the legislation to the parliamentary joint committee on intelligence and security for review and inquiry.
New safeguards have been included, meaning access to data by agencies will have independent oversight.
In addition, the attorney-general's department will have to report annually on the operation of the scheme.