Over one billion people worldwide don’t have any form of identification, making it difficult to access many of the social institutions the developed world takes for granted. A UN organization, the World Food Program (WFP), is testing whether blockchain, the technology that powers bitcoin and ethereum, could solve this ID problem.

WFP launched a project called Building Blocks in 2016 to look into blockchain’s capabilities. Blockchain can help create a decentralized identity for those with no proof of their existence.

“Blockchain [can really be the technology] that underpins digital identity,” says Robert Opp, WFP’s director of innovation. “It can help us link people from different agencies and keep track of what’s going on and who these people are.”

Part of their project includes replacing cash registers in refugee camps throughout Jordan.

Hana Heraaki lives in Jordan’s Zaatari camp for Syrian refugees. She doesn’t use cash or a credit card to purchase groceries. Heraaki and other refugees based in Zaatari instead pay with their eyes.

Here’s how WFP’s blockchain-backed iris scanning device works:

Refugees are registered into the UN’s online biometric database, which includes iris scans, fingerprints, health records and photos. When the device scans a customer’s eye, it links to the UN’s online bank of iris records. Then, it deducts the price of groceries from their WFP monetary aid.

Some refugees were invisible or “stateless” in their homeland even before displacement, like Rohingya from Myanmar and many Sub-Saharan African refugees. Many Syrian and Afghani refugees have a different situation. The majority did hold official citizenship, but their IDs and other official documents were most likely destroyed during bombings or lost during their migration process.

Without an ID, it’s almost impossible to access financial institutions, attend school and go to the doctor. What are normally day-to-day tasks, like buying groceries, are even more complicated for people that don’t exist in the public record.

Over 80 percent of roughly 65 million refugees globally don’t have any form of official documentation to prove their identity, according to the UN.

WFP initially introduced these iris scanners to save money. WFP normally spends $1.3 billion on paper vouchers to help refugees buy groceries. This system eliminates up to 98% of bank-related fees.

But WFP’s device ended up serving another purpose. It established a record of daily transactions which serves as a blueprint of a person’s identity, just like a credit card bill. This information is then recorded on WFP’s blockchain.

The project founders hope tracking refugees’ transactions digitally can replace the need for official paper documentation. Over 100,000 refugees are using iris scanners in Jordan and Building Blocks is set to help 500,000 by the end of 2018.

“We also want refugees to control their own digital identity someday,” Opp said. “This idea of a self sovereign-identity is interesting to us, especially in regards to populations that move around frequently.”

The need for an official digital ID for those who are ID-less is recognized by multiple parties. Belgium donated about $2 million to WFP’s blockchain initiatives in mid-April and ID2020, an alliance fighting that’s working to create digital ID’s for undocumented groups, partnered with Microsoft and Accenture in early 2018.