Yet this is the only argument people have against something like digital voting with anonymized-open results. When voting you select, or are assigned, a secret random key. That key is tied to your ballot which is then published. You can verify your vote was counted, and counted accurately. Observers can verify that exactly the number of people who vote were counted, and it can all be done near instantly and completely openly/transparently.

It creates a system of electronic voting that's even more secure than paper trail audited traditional elections since there's no possibility of ballot stuffing, no possibility of changing votes, no possibility of discarding votes. The only argument against it is that you being able to verify your vote was counted accurately means you could also let somebody else verify how you voted. But the conspiracies where this could be a factor would be too small to matter, or near immediately end up getting busted. Even more so if you add a large 'finders fee' to anybody who exposes such a conspiracy.