Private Internet Voting on Untrusted Voting Devices

This paper introduces a new cryptographic Internet voting protocol, which offers individual verifiability and vote privacy even on completely untrustworthy voting devices. The core idea is to minimize the voting client to a simple device capable of scanning a QR code, sending its content to the web server of the included URL, and displaying a response message to the voter. Today, QR code scanners are pre-installed into mobile devices, and users are familiar to using them for many different purposes. By reducing the voting client to an existing functionality of the voters' personal device, the implementation of the protocol is simplified significantly compared to other protocols. The protocol itself can be seen as a variant of Chaum's code voting scheme with an elegant solution to the problem of distributing the trust to multiple authorities. The approach is based on BLS signatures and verifiable mix-nets. It relies on trustworthy printing and mailing services during the election setup.