I'm curious about this myself but more so on the voter registration side. For example, how do they make sure each voter is casting a single vote? In Illinois

I'm curious about this myself but more so on the voter registration side. For example, how do they make sure each voter is casting a single vote? In Illinois I registered to vote well before the deadline. I showed up to cast my ballot but my name wasn't in the "database." The folks managing the polling station had to manually re-enter all my details into an Android tablet. While this was happening, I took out my phone and scanned the WiFi network of the church I was in. I assume the tablets were connected via wifi. I saw no other connection to the tablet besides a power connection. To my surprised the WIFI was running WEP. Hmm, this day in age you would think WEP would be default=off. This was at a local Church too. So perhaps the tablets use cellular data plans? They get all my PII data entered, I get my ballot, fill it out, and pass it through a machine. The machine is in the corner of the building in a large box so I can't tell if it's hardwired to some network or using the wifi. Later that day (about an hour later after re-entering my details into the Android tablet) I went to the Illinois voter registration web site to look up my name and I can find my details. Anyone have any information on the tablet software? Who writes it? How it's transmitted and stored? What about the electronic ballot counting machines? Are the phoning home some where? The whole setup seems sketchy to me. As an aside: I know a couple people who have homes in different states and claim they can cast multiple votes by driving/flying to the state where they have 2nd home to cast a 2nd ballot.