The new legislation will be "modelled" on provisions contained in the UK's Investigatory Powers Act, Australian prime minister Malcolm Turnbull told the media on Friday last week.
Turnbull said: "What we’re seeking to do, working with the other leading economies in the world, is to ensure that the brilliant tech companies in Silicon Valley and their emulators, bring their brilliance to bear to assist the rule of law. To enable us to be able - not through back doors or any sort of untoward means - but legitimately, appropriately, with the force of law, in the usual way that applies in the offline world, enable our law enforcement agencies to have access to these communications so that they can keep us safe."
Australia's law enforcement agencies are "increasingly unable to find out what terrorists and drug traffickers and paedophile rings are up to because of the very high levels of encryption", Turnbull said. He said encryption leaves some communications "effectively dark to the reach of the law".
"What we need is the cooperation, where we can compel it we will, but we will need the cooperation from the tech companies to provide access in accordance with the law," he said.
Australia's attorney-general, George Brandis QC, explained that the legislation, to be introduced before Australia's parliament in the country's spring, will apply to device manufacturers and service providers.
Those businesses will be obliged to "provide appropriate assistance to intelligence and law enforcement on a warranted basis, where it is necessary to interdict or in the case of a crime that may have been committed, it is necessary to investigate and prosecute serious crime, whether it be counter terrorism, whether it be serious organised crime, whether it be for example, the operation of paedophile networks", Brandis said.
The legislation will be applied "as a last resort" if the technology companies do not voluntarily cooperate in the way the Australian government hopes, he said. The changes will not alter "any existing legal principle", he said.
"It has always been accepted that in appropriate cases, under warrant, there can be lawful surveillance of private communications," Brandis said. "It has always been accepted that in appropriate circumstances there is a compellable obligation on citizens, including corporate citizens, to cooperate with law enforcement authorities in order to resolve or prevent crime."
"What we are doing, is bringing those existing legal obligations up to date. We are contemporising them. The existing law was written before the advent of social media, before the growth in very recent years of encryption of communications to a point at which it is now effectively ubiquitous. So in order to address the new technological developments, we are contemporising existing, well-established legal principles," he said.