Page 20 - 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)

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E. Gerck
the relevant observation is that, at the time the vote is cast, the corresponding
output signal (the contribution of the vote to the election result) is unknown at
the end point.
Thus, both conditions of assuring only one valid ballot per voter and a secret
ballot occur naturally in the VITM; yet we recall that they present difficulties
in classical voting systems.
These initial observations, further qualified by us elsewhere [14, 16–18, 40, 41],
make Information Theory a natural candidate for modeling the voting process.
Mathematics of an ever more elaborate variety is necessary, but to better focus
on our search for more refined concepts, we now claim a metamathematical
argument and directly use well-established results from Information Theory in
terms of the Voter Information Transfer Model.
6.1 Limitations
In our approach we apply Information Theory concepts and results to physical
signals in communication channels and elements that we identify. By extension,
we shall also apply Information Theory to some conceptual signals and commu-
nication elements, which are observable in their effects on the election outcome
of the physical device and yet are non-physical, as they originate from envi-
ronmental or non-functional influences. For example, in section 6.2 we consider
a conceptual coercion channel where an adversary may try to use threats or
rewards in order to perturb how a voter makes ballot choices.
We expect that the Information Theory results extended to those conceptual
signals will generally hold true in the restricted context we use them, not only
given the broad application of Information Theory in many fields [10–13] but
also given our argument (to follow) that any conceptual interference of concern
here must be physically observable in its effects.
However, the only formal claims of this work are made for physical signals,
such as with the voting means. 16

6.2 Interference
To further investigate the requirements of voting system design in providing
election outcome trustworthiness, we now divide the actual election outcome in
two parts: the ideal part, without any interference; and the interference. We
shallcallthe idealpartthe election outcome and consider the actual case to be
that where the election outcome is perturbed by the interference.Interference is
undesirable uncertainty. Interference causes errors.
Interference is anything that can change the election outcome compared with
what the election outcome would have been if the interference did not exist. 17
16
The Witness-Voting Systems (WVS) of Sections 2 and 8 are examples of a voting
means. They are physical devices with physical signals (e.g., a voted ballot).
17
Note that we explicitly exclude from this definition of interference any perturbations
that have no influence on the election outcome. This is not necessary. Interference
could be defined as a vector quantity with other components.