Voters in King County, Wash., will have the opportunity to vote on their smartphones in February. It will be the first election in U.S. history in which all eligible voters will be able to vote using their personal devices.

A district encompassing Greater Seattle is set to become the first in which every voter can cast a ballot using a smartphone, radically increasing accessibility for many voters with disabilities who face barriers to in-person or absentee balloting. The program is being piloted in a local election Feb. 11. Election security experts expressed strong concerns that any voting method that requires transmitting information over the internet is vulnerable to hacking.