Oblivious Voting—Hiding Votes from the Voting Machine in Bingo Voting
Dirk Achenbach, Bernhard Löwe, Jörn Müller‐Quade, Jochen Rill · 2016
When designing an electronic voting scheme it is notoriously difficult to guarantee the secrecy of the vote as well as the correctness of the tally, even in the presence of a malicious adversary. Research in (offline) cryptographic voting schemes has largely relied on a trusted voting machine for guaranteeing security. We alleviate part of this trust requirement. Our scheme ensures the confidentiality of the vote even in the presence of an honest-but-curious voting machine. We improve on Bohli et al.’s Bingo Voting scheme (Bohli et al., 2007). Bingo Voting already guarantees the correctness and public verifiability of the election in spite of a malicious voting machine. The voting machine learns the voter’s input however, and is trusted not to violate ballot secrecy. Our novel construction’s output is identical to that of Bingo Voting. We devise an electro-mechanical Physical Oblivious Transfer (pOT) device to remove that trust requirement by hiding the voter’s choice from the voting machine. The pOT device is realised in such a way that the voter merely operates a button to express her choice. Our construction is thus particularly user-friendly.