A number of technological schemes have been suggested for fixing security problems related to electronic voting. The most common is to require that each machine generate a voter-verified paper ballot and to audit a sample of paper ballots after an election. Some states (including California) have moved towards this method.
Another proposal is to use encryption to ensure voters and observers that votes haven't been tampered with. In one such scheme, developed by Wallach and colleagues and called VoteBox, when voters completed a ballot, their identity and a record of their vote would immediately be encrypted and posted online. Each machine would also issue an encryption key to voters so that the record could be decrypted to make sure the vote had been recorded correctly.