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.
Why would you want a zero-knowledge database? You want the exact opposite: you want to be able to tie the vote to a person, which is why ballots are associated strongly to your identity and why counting physical ballots remains so important.
The whole point with voting at least in a civic context is that your vote isn’t tied to you, ie. nobody can actually tell who you voted for; they need to know that each vote is valid but not who cast each vote. You do need to have ID (or whatever the process is in your specific country) to be able to vote, but at least here the foldable piece of paper you actually put your candidate’s number in has absolutely no identifying information on it, it just gets stamped by an election official when you go to put it in the ballot box.