system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can Electronic Voting machines never be as secure as Paper ballots ?
gpt
Electronic voting can either be secure or anonymous, pick one. Unfortunately, democracy demands both. We need secure voting to ensure that the votes cast are the votes counted. But we also need anonymous votes to prevent voter intimidation- people need to be confident that who they vote for won't be held against them. Your vote isn't really yours if the winner plans to jail all of the loser's voters, or if your boss will fire you for voting for the wrong person.

Securing elections revolves around one basic principle: everyone wants to cheat so you can't trust anyone, but they also want to prevent the other side from cheating so you make everything happen out in the open where each side can call out the other if they see anything fishy. You go to a public place to cast your vote, where people from both sides are making sure no one is intimidating you. You're not allowed to vote until after you've confirmed your identity, and that you've only voted once. You fill out your ballot in a shielded area, where people can see that you're voting but they can't see who you're voting for. After you fill out your ballot, you fold it so no one can see who you voted for and publicly place the ballot in a sealed box, where anyone can see that that you're only putting in one piece of paper. At no point is the ballot box left behind with just people from one side observing it, so that no one has time to stuff it. The box's seal is checked before being opened and counted. The counting takes place in an area where people can observe (some places even have webcams so you can watch from home). 

The problem with electronic voting is that too much of it can't be observed. You have a computer running software that you're pretty sure is accurately counting the ballots, but you can't actually prove it. Even if the software is open source, you can't guarantee that the software running on the machine is identical to the software that was open sourced. Even if it was compiled on the machine and you could inspect the source to verify it was the same (which would massively slow down voting), you couldn't guarantee that no one had messed with the compiler to make it output the wrong machine code even given the right input. Even if you took a checksum to verify it was the same, you couldn't guarantee that no one had messed with the checksum generator. There is no way to observe a running program that can't be messed with. (you can probably get close with dedicated hardware that can't be reprogrammed, some very heavy mathematics, and a whole bunch of electron microscopes but it's still not something where you can observe every voter at every polling location like you can with in-person voting)

Yes, it's possible for there to be fraud with in-person voting. Someone could pretend to be someone else, for example. But each time you impersonate someone, you only get one extra vote. In order to get enough extra votes to actually influence a national election, you'd have to involve so many people that it would be near impossible for someone to not get caught. The difference between fraud on a paper voting system and fraud on an electronic voting system is that if you manage to hack the electronic voting system, you're a lot more likely to be able to change a lot more votes and actually impact the election.