All travelers who want to fly to the U.S. are required to present proof of a negative Covid-19 test. For now, that proof takes the form of a printout of a test result, or a photo of that result — creating opportunities for misunderstandings or potential fraud. Newly launched digital initiatives are hoping to clear up any ambiguity, standardize information, and share it securely.

International travel is likely to be the first industry to employ new digital passports. One of the first flights to trial a new “digital passport” embedded with vaccination information and test results took off Thursday morning, a Qatar Airways flight from Doha to Istanbul.

Fliers log in to the Travel Pass app using FaceID on their smartphone, then take a selfie to authorize access. They can then scan their passport using the camera on the phone. From there, passengers can add their itinerary, vaccination certificates, and Covid-19 test results.

As part of this trial, passengers in Doha can go to a local medical center, which will send their test results directly to the app. The app shows a green checkmark to say you’re ready to travel. The airlines also have access to the backend system, allowing for contactless and paperless verification.

“What it will do is give people and the authorities confidence that your documentation is correct that you have been vaccinated. You don’t have to carry pieces of paper around, which you could lose and get into a bind with the authorities,” Qatar Airways Group CEO, Akbar Al Baker, told NBC News.

Both the International Air Transport Association, which developed the Travel Pass, and the airlines using it, say the Travel Pass will adhere to strict data privacy restrictions.

“It also will give you confidence as a passenger that your data that you have put into the system stays on your smartphone and is not being shared with anybody else,” Al Baker said.

Over a dozen airlines have already signed up to trial the pass, including Emirates, Singapore Airlines, and Qantas. The pass will officially debut at the end of March.

Some governments and airlines have begun making their own apps or allowing for other digital systems. British Airways and budget airline Ryanair have started letting passengers upload their Covid-19 and vaccination test results along with their other personal booking information when booking online. But Al Baker said having a multitude of digital passport formats is not ideal.

“We want it to be a standard form accepted by the entire world airport community and immigration community,” Al Baker said.

Without the ability to trust Covid-19 tests — and eventually vaccine records — many countries will feel compelled to retain full travel bans and mandatory quarantines.

For international travel, governments will likely require some form of proof of vaccination in the near future, similar to how some countries now mandate vaccinations for other diseases, like yellow fever or polio, airline executives say. But there are not currently plans for enforcing those on domestic flights.

“I don’t see that happening in the U.S.,” Delta CEO Ed Bastian told NBC News in a recent interview.

United and American Airlines are both on the IATA Travel Pass advisory group, providing input into the development of the app, but neither has confirmed when they will trial the feature.

In October, a United flight from London to Newark did a trial run of a Covid-19 status smartphone-based system called CommonPass.

“Without the ability to trust Covid-19 tests — and eventually vaccine records — across international borders, many countries will feel compelled to retain full travel bans and mandatory quarantines for as long as the pandemic persists,” said Dr. Bradley Perkins, chief medical officer of The Commons Project, the nonprofit digital platform builder that developed the system, in a statement.

“With trusted individual health data, countries can implement more nuanced health screening requirements for entry,” Perkins said.

In January, President Joe Biden issued an executive order that asked government agencies to “assess the feasibility of linking Covid-19 vaccination to International Certificates of Vaccination or Prophylaxis” and the capability of making digital versions.

On Monday, Andy Slavitt, a senior adviser on Biden’s Covid task force, said the administration has a series of guiding principles about vaccine passports but does not believe the data should be held by the government.

Several private sector initiatives are underway, including a partnership between tech companies like Microsoft and Oracle and health organizations such as the Mayo Clinic, Change Healthcare and Evernorth.

“It needs to be private; the data should be secure; the access to it should be free; it should be available both digitally and in paper, and in multiple languages; and it should be open source,” Slavitt said.

Air travel plunged in the U.S. up to 60 percent as lockdown orders and travel restrictions curbed nonessential travel.

Glimmers of hope have begun to emerge as vaccinations have increased and infections rates have dropped overall, although flattening and even rising rates in some areas are prompting concern. Airlines boasted their highest traveler levels this past weekend.

Privacy and human rights advocates are concerned that requiring a digital vaccination passport could create an unfair two-tier system between those who have easy access to them and to vaccines and those who do not.

The vaccine passports for air travel carry the danger of creating “inequity” and “false assurances of public safety,” said Nita Farahany, a professor of law and philosophy at Duke University, in an email.

Liberty, the U.K.’s largest civil liberties organization,warned in a statement: “It’s impossible to have immunity passports which do not result in human rights abuses.”