Researchers from several institutes worldwide recently developed Quarks, a new, decentralized messaging network based on blockchain technology. Their proposed system could overcome the limitations of most commonly used messaging platforms, allowing users to retain control over their personal data and other information they share online.
I wish I could find this again, but I read an old article where someone proposed paper ballots that are given a unique ID number. They are marked in the middle by the voter, then scanned to be counted electronically, then part of the ballot with a copy of the ID number is kept by the voter. The rest of the ballot is retained in the ballot box. Later on, if the voter wants to make sure their vote was counted correctly, they can go to a website, enter the ID number and it will display the votes for that ID. This is an electronic counting system with a physical paper backup that’s verifiable by the voter. I like that system. I was only bringing up blockchain because OP asked about possible uses for that tech.
But you don’t want that either. This opens up a way for people to demand others to prove they voted a certain way - I.e. abusive family could force all family members to vote the same. Paper ballots shouldn’t ever be identifiable back to anyone.