Australians are now receiving digital vaccine certificates on their phone, in what many hope is a major step towards returning to pre-Covid life.
The Prime Minister aims to have them recognised for international travel within months. But where they'll be needed, and how far they'll take you, remains unclear for now - and experts are warning of a logistical, political, and legal minefield which will need to be tiptoed through.
RMIT cyber expert Matt Warren warns hundreds of different identification systems, with various levels of security and accepting different vaccinations, will be a "recipe for disaster".
"It's a very complex situation. I don't think that complexity has really been understood at the moment," he says.
"An Australian customs officer would have no idea if someone from South Africa was carrying a real or fake vaccination certificate.
Warren expects complex negotiations will be required, meaning Australians' travel options will be staggered over a number of years as the government strikes travel-bubble deals.
"This idea that on a certain date the whole world is going to open is just a fantasy. I just cannot see that happening with the technology that's being proposed," he says.
The EU has begun rolling out a digital travel pass for unfettered travel across the bloc, though flaws are already being exposed after a German security company managed to register a dead person.
And after independent senator Rex Patrick created a fraudulent vaccination certificate via Medicare, Warren warns there will be high motivation and "so many ways to manipulate" checks here, particularly if they are hastily implemented.
"Anti-vaxxers want to travel, they want to have the same opportunities as people who have been vaccinated. So they'll be trying to find ways to exploit [it]," he says.
Evidence of that is already emerging in North America, after Canadian authorities fined an unvaccinated pair returning from the US with fake proof-of-vaccination documents.
Warren also cautions that a new market for counterfeit IDs on the Dark Web, an unregulated section of the internet rife with crime, could expose people to other forms of serious crime.
He argues a national ID card, onto which vaccine certificates could be loaded, would be the most secure option.
Warren claims the card would also remove the potential for discrimination, given elderly and vulnerable people are less likely to own smartphones.
While conceding the idea would be politically unpalatable, he says governments have been willing to implement previously unthinkable measures during the pandemic.
"We're already making hard decisions. We've had lockdowns in Victoria, we had curfews from the state government. It's about strong leadership in adverse situations," he says.
Roadblocks facing unvaccinated Australians are unlikely to end at international travel, after Morrison flagged "common sense" restrictions on home soil.
The NRL is mulling a ban on spectators who refuse to get vaccinated, while fully vaccinated Australians might be exempt from border closures.
But Human Rights Law Centre executive director Hugh de Kretser warns vaccine passports are fraught with human rights risks which need to be carefully weighed.
With herd immunity not requiring complete vaccination, De Kretser says clear exemptions on medical and religious grounds need to be established.
"This is such a difficult issue to get right from a policy perspective, and there is human rights risk all over it," he says.
De Kretser views high-vaccine uptake as critical to restoring freedoms, but warns there are "minimum floors" beneath which society cannot sink.
"It's the type of service that might be denied to unvaccinated people that is vital in assessing the justification," he says.
"You shouldn't be requiring a vaccine passport for essential services like food or going shopping at the supermarket.
"You'd be imposing big restrictions on people's quality of life and dignity."
De Kretser accepts that reasonable people will disagree on where the line is drawn, but insists the baseline needs to be "more carrot and less stick".
"The stick approach comes with more human rights and legal risks. I am much more worried about excluding people from services than I would be about offering vaccine incentives," he says.
But the quickly evolving health situation shifts the goalposts on what governments can demand of their citizens, he argues.
"Context is critical in this. The levels of community transmission, vaccination rates, and public health evidence around risk are all key considerations in assessing the justification for vaccine passports," he says.
De Kretser argues the higher transmissibility seen during the Delta outbreak has tipped the balance back towards justifying harder measures - but they should be scaled down to mirror any decreasing threat.
"If you achieve herd immunity, and the risk becomes as low as other diseases which don't require a vaccine passport, it would be extraordinarily hard to justify why you would make an exception for Covid," he says.
The government claims lockdowns will effectively be a thing of the past once 80 per cent of the eligible population is vaccinated.
But Grattan Institute chief executive Danielle Wood claims that figure could still see outbreaks overwhelming Australia's health system, and states continuing to implement restrictions.
She is pushing for mandatory vaccination in "higher-risk settings" - including large events, domestic flights, and restaurants - from the new year, once every Australian has had the chance to get vaccinated.
"There are some [people] who will be harder to convert, and certainly we think vaccine passports are one tool in the arsenal," she says.
While accepting the need to balance health concerns with civil liberties, she insists there is no "magical world" where mass death can be avoided without restrictions.
She says lessons can be learned from France, where proof of vaccination is required in a range of public venues.
"We know what the alternative is ... lockdowns, which are frankly far more coercive," she says.
"We certainly saw in France a particularly big rise in vaccination rates among younger people, which seemed to be driven by that policy."
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They also prompted 200,000-strong demonstrations across the country, as protesters clashed with police in Paris.
Although anti-vaccination sentiment is higher in France, anti-lockdown protests in Sydney demonstrated the potential for anger to bubble to the surface in Australia.
But ANU researcher Adam Henschke is optimistic resentment will fade as the benefits of vaccination passports become clear.
"I think it will bolster anger and loud protests. [But] my hope is it's a relatively and increasingly small contingent of people," he says.
Henschke concedes some people will inevitably view vaccine requirements as draconian. He is urging politicians to resist seizing on early system failures, like people being denied services due to technical hiccups, for political gain.
"There's usually a fair bit of goodwill at the start. But once things start breaking down, you see basically blaming [and] buck-passing," he says.
"Political leaders, and commentators who have a big audience, have a responsibility to not be sensationalist.
"[Resentment can grow] if these things aren't handled well, and especially if political leaders engender distrust in these processes more generally."
Victoria, the Northern Territory, and Tasmania are preparing a model for exactly how vaccinated people can live their lives, to be presented to national cabinet in the coming weeks.