  Postal voting is growing rapidly in the U.S., with 43% of voters casting
ballots by mail in 2020, yet until recently there has been little research
about extending the protections of end-to-end verifiable (E2E-V) election
schemes to vote-by-mail contexts. The first - and to date, only - framework to
focus on this setting is STROBE, which has important usability limitations. In
this work, we present two approaches, RemoteVote and SAFE Vote, that allow
mail-in voters to benefit from E2E-V without changing the voter experience for
those who choose not to participate in verification. To evaluate these systems
and compare them with STROBE, we consider an expansive set of properties,
including novel attributes of usability and verifiability, several of which
have applicability beyond vote-by-mail contexts. We hope that our work will
help catalyze further progress towards universal applicability of E2E-V for
real-world elections.
