From Scantegrity Wiki
Notions of Voter-Verifiability
E2E - End-To-End
End-To-End (E2E) voting systems provide guarantee of ballot (or vote) integrity from casting to tallying.
In general, the technical process of vote tallying can be broken into two general steps:
- Voted ballots are gathered into a collection of voted ballots, and
- the collection of voted ballots are counted to produce the final tally.
The problem with the way that most elections handle these steps lies in an integrity gap between these two steps. Though paper audit trails or manual recounts can help to protect the integrity of the tallying step, they do not ensure that ballots are not removed or replaced, or that no marks added to them (i.e.,to fill in undervoted contests with votes for a desired candidate or to overvote and spoil votes for undesired candidates). E2E systems claim to solve this problem by presenting a way to guarantee the integrity of the ballots from casting to tallying.
In general, E2E systems make three claims:
- That any voter can verify that his or her ballot is included, unmodified, in a collection of ballots,
- That any voter (or independent third party) can verify that the collection of ballots produces the correct final tally, and
- That no voter can demonstrate how he or she voted.
Note that the problem of extra ballots being introduced between the collection stage and the tallying stage is not included in the definition of E2E. This is because by comparing the number of votes cast with the number of registered voters who voted, this problem can be eliminated trivially.
The E2E property is related to another integrity assertion, software independence, but provides stronger criteria. All E2E systems are, by definition, software independent. The Election Assistance Commission lists E2E systems as a form of Independent Verification system in the 2005 Voluntary Voting System Guidelines.