(Or, why doing the obvious thing to improve voter throughput in Harris County early voting would exacerbate a serious security vulnerability.)
I voted today, using one of the many early voting centers in my county. I waited roughly 35 minutes before reaching a voting machine. Roughly 1/3 of the 40 voting machines at the location were unused while I was watching, so I started thinking about how they could improve their efficiency. If you look at the attached diagram, you’ll see how the polling place is laid out. There are four strings of ten Hart InterCivic eSlate DRE (paperless electronic) voting machines, each connected to a single controller device (JBC) with a local network. These are coded green in the diagram. On the table next to it is a laptop computer, used for verifying voter registration. This has a printer which produces a 2D barcode on a sticker. This is placed on a big sheet of paper, the voter signs it, and then they use the 2D barcode scanner, attached to the JBC, to read the barcode. This is how the JBC knows what ballot style to issue to the voter, avoiding input error on the part of the poll workers. I’ve used the color blue to indicate all of the early voting machinery, not normally present on Election Day (when all of the voters arriving in a given precinct will get the same ballot style).