West Virginians currently living overseas began using a blockchain-enabled mobile voting app to cast absentee ballots for the midterms on Friday. A Boston-based startup called Voatz created the app using blockchain encryption so that people can vote remotely and securely if a polling place or dependable mail services are unavailable.

West Virginia officials are particularly promoting the app for use among military members who have been deployed abroad. “There is nobody that deserves the right to vote any more than the guys that are out there, and the women that are out there, putting their lives on the line for us,” West Virginia Secretary of State Mac Warner told CNN last month.

The state ran a pilot program for the new voting option in two counties in May along with four independent audits, and it will now be available to overseas residents from 24 counties for the November elections. These voters still have the option to use paper ballots if they so choose. Tusk Montgomery Philanthropies, a firm founded by venture capitalist Bradley Tusk, is working with West Virginia to fund the endeavor. “Democracy would work a lot better if more people can vote,” he told Metro News, a West Virginia outlet. “I personally would love to see a world one day where everyone can vote securely on their phone.”

Blockchain technology allows people to maintain a list of transactions that is stored on all the computers participating in a particular network. These computers work together to verify additions to the list and to encrypt the records so that malicious actors cannot tamper with them. Blockchain is most commonly used to facilitate the mining and trading of cryptocurrencies like Bitcoin, but Voatz is taking advantage of the technology to keep track of votes.

Voters register for the app by uploading a selfie and photo identification, and they must go through a multifactor authentication process to log in. However, as CityLab points out, some election technology experts have raised concerns about the use of an app to send digital ballots via blockchain. Researchers from the National Academies of Sciences, Engineering, and Medicine argued that malware on a smartphone could alter a vote before it even reaches the blockchain. Joseph Lorenzo Hall, the chief technologist at the Center for Democracy and Technology, told CNN, “It’s internet voting on people’s horribly secured devices, over our horrible networks, to servers that are very difficult to secure without a physical paper record of the vote.” Voatz developers have claimed that the app can detect if malware has infected a device and will only run on particular smartphone models that have the latest security updates.

While West Virginia is the first state in the U.S. to try blockchain voting for an election of this size, countries like Russia, Japan, Switzerland, and Ukraine are also implementing the technology for recording votes.