EDIT: My pessimism aside how feasible would it be to get a code upon voting that you could later go online with and compare to what was actually tallied under that system? With the prevalence of personal pocket cameras If something funny starts happening it seems it could get found out quick. It sounds like plenty of people would take a picture of their vote with the code onscreen and get really public with photographic evidence if stuff does not match up.
In the lengthy thing I deleted, I had the electronic vote you cast checkable against a receipt slip with voterID and one-time-salt used to access and confirm the record associated with that voter's intention
and the necessary conformation that the tally prior to voting plus the intended vote becomes the tally immediately after voting.
It would not, itself, show the vote cast (so no pay-for-votes possibilities) but could be used to give reassurance. So long as the back-end is assured - an issue with paper-vote counting and electronic alike where taking a photo of a cast ballot doesn't prove
anything about how/whether it is subsequently processed.
It needs other measures, to protect against electoral fraud (whether vote-buying or back-end massaging) which is why I deleted my 'manifesto' after writing it. Far too wordy for what I'd been trying to say.