STROBE-Voting: Send Two, Receive One Ballot Encoding

Numerous designs for end-to-end verifiable voting systems have been proposed in recent years to accommodate in-person voting scenarios and Internet voting scenarios, but very few have been offered to support vote-by-mail and none that are practical with current equipment and processes. This work describes a simple approach to end-to-end verifiable vote-by-mail that can be implemented with little change to existing processes. A specific architecture is described in this work, but the basic technique can also be used to enable many existing end-to-end verifiable systems to support vote-by-mail. Since most election jurisdictions utilize some combination of in-person voting and vote-by-mail, there is great value in an approach which allows both modes to be unified into an end-to-end verifiable system that produces a single verifiable tally.