The first thing is to end voting for weeks leading up to an election.
No, the first thing is long prison terms for officials committing vote fraud and jail time (read chain gang picking up trash along the road side while wearing a pink & chartreuse polka dot jumpsuit with a Im a Vote CHEAT sign front & back) & fines for people who voted multiple times.
Another high tech solution would be:
“Election ink” has been used in many countries for a long time:
No higher form of treason than voter fraud - kill them and it won’t take long to put integrity back into the system.