Page 23 - Towards Trustworthy Elections New Directions in Electronic Voting by Ed Gerck (auth.), David Chaum, Markus Jakobsson, Ronald L. Rivest, Peter Y. A. Ryan, Josh Benaloh, Miroslaw Kutylowski, Ben Adida ( (z-lib.org (1)

The Witness-Voting System
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Thus, even though useful to define the physical scope of each element, bound-
ary definitions are not limiting in terms of either interference influence or
prevention.
Our framework [VITM, Requirements, WVS] predicates the need for a com-
prehensive, cross-boundary approach. In order to minimize interference, we con-
sider conceptual and physical error/correction channels in the VITM to define
Requirements (Section 7) that work togetherwith aconformingvotingmeans
(the WVS, Section 8). 22
6.3 Optimal Design
Election outcome trustworthiness requires that a voting system produces results
with high accuracy and reliability (see the respective definitions in Section 3,
Table 2). This section shows how 100% accuracy and reliability can be achieved
and verified as closely as desired, which we call the optimal design.
From Information Theory we use the concept of channel, as thatpartof
a communication chain in which signals are transmitted from a sender to a
receiver. An important channel in a voting system is shown below, in sending
information from A to B:
(A: what the voter sees and casts) =⇒ (B: the tally results)

where, if the channel is vulnerable to interference, it may not be possible to reli-
ably send A to B. The fundamental problem of voting [18] is that of reproducing
at B the same information that was sent from A. Or, as often stated, how can
we prove that the vote received at a ballot box, and tallied, is the same vote
that was seen and cast by a voter?
This question is not easier to answer if the voter is close to the ballot box, or
far away. Distance plays no role, contrary to what one might think at first. The
essential problem is that the voter is not and cannot be inside the ballot box,
and cannot follow the ballot all the way to the tally results, hence the voter has
no way of knowing if what was sent through that communication channel (which
may be very short) was what was received (and tallied).
Specifically, what we desire is stability in the presence of interference meaning,
in a broad sense, “invulnerability to potentially corrupting influences”. This
corresponds to the concept of reliability in Information Theory, with the same
definition used here (Section 3, Table 2).

22
For example, gerrymandering is a conceptual attack that can be set up in spite of
any security assurances of the voting means. However, if a conforming voting means
allows voting from any location then it becomes possible to deny in the requirements,
as broadly as desired, any geographical restrictions that could be manipulated for
gerrymandering [42]. As another example, visual accuracy errors by the voter in
choosing the intended ballot options (i.e., a conceptual interference) can be prevented
physically by offering the voter a final screen with a summary of all the votes for
confirmation.