Australians could one day wave their hand in front of their computer screen to access internet content as part of a push to keep young people safe online.
It's just one technology being assessed as part of a trial of age verification and assurance measures, as the government plans to introduce age limits for social media.
However, a strict approach limiting internet access could have unintended consequences, warned communications department officials overseeing the trial.
Rather than hard age verification, the department is focused more on age assurance to reinforce the broader reforms, communications department deputy secretary James Chisholm said.
"One of the risks with a strict verification approach is that people will then avoid it altogether, and we won't be then achieving a policy objective of wanting to prevent exposure by children to extreme content or adult content," he told Senate estimates on Tuesday.
Age assurance uses technologies and tools to make an assessment about whether a person is likely to be in a particular age bracket, whereas age verification requires users to provide hard proof they are of age, for example by using identity documents.
Andrew Irwin, assistant secretary of the online safety branch, said similar measures implemented overseas had not worked as intended.
"We've seen examples in the United States where age verification was introduced for access to Pornhub, traffic from that particular jurisdiction dropped by 80 per cent," he said.
"Which suggests either people are going to darker websites or they're using VPNs, neither of which are good policy outcomes."
Age assurance measures which "wrap around" the user could allay fears that they need to disclose their identity and prove more effective.
"Age assurance includes both verification and estimation, and there are a wide range of technologies that can be used for estimation," Mr Irwin said.
"We have had some providers suggest to us that waving a left hand in front of the screen, they'll be able to provide above 90 per cent accuracy.
"But that is exactly why we're running the trial, so that we can get an independent assessor to look across all the technologies and consider them against a range of criteria."
The government is planning on introducing age limit legislation to parliament before the end of the year, but has yet to specify what age it would be set at.
The age assurance trial is likely to conclude in the first half of 2025.
The South Australian government has flagged it will move to ban social media accounts for young teenagers, prompting support from other states and concerns from youth safety advocates about potential unintended consequences.
