Paper can be problematic as well. There needs to be some form of circular verification. As a rough example: Number the options on the ballot sequentially. When a ballot is submitted, print the tally on a receipt along with the ballot ID. Ballot goes off to be counted, receipt goes into a third party "audit" box, voter keeps a copy of the receipt. As blocks of votes are counted, sum the tallies - if they don't match that of the auditors, you have a problem - something has changed on the ballots, in the database, etc. If you want to verify your own ballot, add the numbers up yourself and look up the sum for your ballot ID.