New Zealand's vaccine passport is still being designed but health officials say the digital certificate will contain a QR code and a secure digital signature.
People will have the option to print off a hard copy or keep it on their phone.
Act Party leader David Seymour has questioned how exactly people's vaccination status would be verified.
"How can anyone prove that they've had a vaccination if they didn't put their NHI in at the time?
"When I was vaccinated, I was given a pretty flimsy piece of cardboard with handwriting on it and the nurse said 'you should probably take a picture in case you lose it' and thankfully I did because I have."
Ministry of Health data shows only 21 per cent of Māori are fully vaccinated - 13 per cent less than people in the European or other category.
Te Pāti Māori co-leader Debbie Ngarewa-Packer said unless that changed, the certificate could become a cause of discrimination.
"We have to be able to create something that's equitable and recognise the fact that Māori are still far behind the ball when it comes to having a defence against Covid."
Seymour said the Government needed to consider a verified exemption for those who could not be vaccinated for medical reasons.
"I think it would be a real shame if there wasn't a place in any vaccine passport policy for them that recognises that some people just won't be able to be vaccinated and the reason the rest of us should get vaccinated is actually protecting them."
Auckland technologist Andrew Chen said a verified exemption was achievable.
"There are ways to design the certificate so that you might be able to notify that this person is not vaccinated, they have a good reason but we're not going to tell you what the reason is."
International travel is one of the main drivers for a vaccine passport - at the moment, people can request a letter from the Ministry of Health that confirms they are full vaccinated.
But whether or not countries recognise it as a formal proof of vaccination is not guaranteed.
Officials are working to ensure what's rolled out in December can be recognised by as many countries as possible.
But Chen said the government needed to be upfront on whether the vaccine passport could be used in a domestic setting too.
"I think there is a concern that once this is widely available, that a private sector player could decide that you have to prove vaccination status in order to enter a premise or employers may require you to prove that you're vaccinated for health and safety reasons before you're allowed to go to work. So I think there are concerns there that the government needs to get ahead off."
National Covid-19 Response spokesperson Chris Bishop said people should be able to prove their vaccination status through the government's Covid-19 Tracer app.
"People are well familiar with the app and the tracer technology, and I think having electronic verification that you are doubly vaccinated I think is going to be important into the future. It's just inevitable that there will be requirements for people to be doubly vaccinated for some things."
But what exactly those things are is a debate Aotearoa is yet to have.
- RNZ