Even if there is registration, that only helps if I can verify that the entire chain only includes registered people. So how can I verify everyone who voted is

Even if there is registration, that only helps if I can verify that the entire chain only includes registered people. So how can I verify everyone who voted is registered, without also knowing which vote is from which person? Maybe have a separate record for "this person voted" and another record for "1 vote for X", with encrypted references back and forth? Then you could at least verify that there are an equal number of both records, that all the identities are valid and only used up to once, and tabulate the final results. It would still be possible for someone who didn't vote to have a false vote logged, but that is a more narrow attack.