Distributed Protocols at the Rescue for Trustworthy Online Voting
Robert Riemann and Stéphane Grumbach
Inria Grenoble Rhône-Alpes, Lyon, France
Keywords:
Distributed Online Voting, Trust, Distributed Protocols, Bitcoin.
Abstract:
While online services emerge in all areas of life, the voting procedure in many democracies remains paper-based
as the security of current online voting technology is highly disputed. We address the issue of trustworthy
online voting protocols and recall therefore their security concepts with its trust assumptions. Inspired by the
Bitcoin protocol, the prospects of distributed online voting protocols are analysed. No trusted authority is
assumed to ensure ballot secrecy. Further, the integrity of the voting is enforced by all voters themselves and
without a weakest link, the protocol becomes more robust. We introduce a taxonomy of notions of distribution
in online voting protocols that we apply on selected online voting protocols. Accordingly, blockchain-based
protocols seem to be promising for online voting due to their similarity with paper-based protocols.
1 VOTING IN THE DIGITAL AGE
Online services have emerged during the last decade
in most areas of every day life. Online banking, online
auctions, online shopping, online learning and online
dating, to name a few, have become serious alterna-
tives to their offline counterparts for the additional
convenience they provide. Most online services are
available 24 hours a day 7 days a week and can be
accessed from any place with an internet connection.
In particular, online social networks gained a lot of mo-
mentum. Many people are permanently connected to
communicate with friends and colleagues. The social
network Facebook, for instance, reports on 1.71 bil-
lion monthly active users as of June 2016 which is
more than 20 % of the world population. The adoption
of online services increases further with the global
dissemination of internet-enabled devices.
In these circumstances of pervasive online services,
the paper-based voting procedure used to carry out
elections in many democracies appears like a legacy
from the past. This is even more the case for the gener-
ation of Digital Natives that is used to the convenience
offered by online services.
Paper-based voting requires voters to cast their
ballot within a given time frame at a particular location.
In contrast, remote electronic voting, in short online
voting, allows voters to cast their ballot from home or
any other place. The time and effort to vote decreases.
Consequently, the overall voter turnout is expected to
increase (Carter and Bélanger, 2012). Moreover, the
ballot casting is carried out using a special software
which improves the voter convenience as the ballot
presentation considers for instance the voter’s spoken
language and possible disabilities.
The voter convenience is especially important if
voters are often asked to vote, e.g. for elements of
direct democracy such as referenda. Not only doubts
in the integrity of the voting outcome, but also a low
voter turnout can negatively impact the legitimacy of
the result.
Despite the advantages, only few countries employ
online voting for general elections, e.g. Estonia (Ülle
and Martens, 2006), Canada (Goodman, 2014) and
Australia (Brightwell et al., 2015), and for those, se-
curity concerns have been addressed repeatedly by the
scientific community (Springall et al., 2014; Halder-
man and Teague, 2015). Other countries have aban-
doned online voting trials or banned online voting for
their insufficient security, as it happened in Germany.
In fact, the provision of the same set of security prop-
erties as known from paper-based voting for online
voting proves to be challenging with no universal solu-
tion, but with different potential concessions.
In this paper, we address the issue of trustworthy
online voting protocols with regard to the potential of
distributed protocols. Starting from paper-based vot-
ing with its broadly accepted trustworthiness (Sec. 2),
we give a high-level review of the principle security
concepts of online voting protocols and deliver an
overview of their trust assumptions (Sec. 3). The ca-
pacity of authorities and of the voters defined by the
Riemann, R. and Grumbach, S.
Distributed Protocols at the Rescue for Trustworthy Online Voting.
DOI: 10.5220/0006228504990505
In Proceedings of the 3rd International Conference on Information Systems Security and Privacy (ICISSP 2017), pages 499-505
ISBN: 978-989-758-209-7
Copyright
c
 2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
499

protocols are hereby of primary concern. We show that
the trustworthiness in those approaches is limited due
to the concentration of power and argue hereinafter
that distributed protocols are promising to increase
the trustworthiness due to their similarity with paper-
based protocols. Bitcoin, an electronic currency with
no trusted authority, is introduced in Sec. 4. More-
over, the development towards online voting is com-
pared with those to Bitcoin and BitTorrent. Sec. 5 is
dedicated to the prospects of distributed protocols for
trustworthy online voting. Then in Sec. 6, different
notions of distribution are introduced in order to anal-
yse a selection of existing online voting protocols for
their degree of distribution. Our conclusion follows in
Sec. 7.
Our findings motivate our ongoing research on
distributed online voting protocols with a novel dis-
tributed protocol currently in preparation for publica-
tion.
2 PAPER-BASED VOTING
The paper-based voting protocol used today in many
democracies is the result of a development rooted in
Ancient Greece where pebbles were casted in an urn
for votings. Since then, many provisions have been
added to ensure the voting outcome reflects indeed the
aggregated choice of all eligible voters. Neglecting
local particularities, we give a sketch of a paper-based
voting protocol to recall afterwards how basic security
properties are implemented.
Preparation Phase. The voting station is the ded-
icated location to receive voters on voting day and
is run by volunteering voters that become thus occa-
sionally voting officers. For large numbers of voters,
the voters are partitioned by locality to a reasonable
number of voting districts with each one voting station.
Every station is provided with undistinguishable vot-
ing ballots and a list of eligible voters issued by the
central voter registry.
Casting Phase. On arrival at the voting station, vot-
ers have to present a proof of identity in order to pro-
ceed to the casting. Once the voter is confirmed to be
eligible, a blank ballot is handed out and the voter list
is annotated accordingly to prevent that voters can get
more than one ballot. Under public supervision, the
voter enters alone the voting booth to fill and fold in
secret the paper ballot. Again under public supervi-
sion, the filled ballot is thrown into a transparent ballot
box.
Aggregation and Evaluation Phase. Once, the
casting phase is terminated, ballot boxes are opened
and ballots are tabulated to determine the tally that is
published independently along with the derived voting
outcome, e.g. using the majority rule.
Verification Phase. Every voter is allowed to attend
all phases to supervise the compliance with the voting
protocol.
Conflicting Security Properties. Paper-based vot-
ing resolves the dilemma of voting protocols to en-
sure secrecy of the ballot and voter eligibility at the
same time (Lambrinoudakis et al., 2003) in a straight-
forward way. Voting officers and voters control that
only eligible voters get one single paper ballot and that
every voter puts only one ballot into the ballot box.
Secrecy of the ballot is provided, because every voter
fills and folds its ballot alone and once deposited in the
ballot box, all ballots are indistinguishable and cannot
be linked back to the voter. By eye-sight, ballots can
be followed from its distribution, through its casting
into the transparent ballot box until the tallying of all
ballots. Verifiability is realised by the observation of
the physical ballot transport, which is called chain of
custody. This verification does not require any special
knowledge. Hence, neither trust in the authority car-
rying out the voting, nor in employed technology is
imposed.
3 ONLINE VOTING CONCEPTS
The development of online voting protocols, that pre-
serve the security properties known from paper-based
voting, is proven to be difficult. Electronic ballots
can be cloned with no effort and their physical trans-
port via wire cannot be observed. That is why special
cautions must be taken to prevent the casting of ille-
gitimate ballots, e.g. of ineligible voters or voters that
seek to cast more than one ballot. Various concepts
have been considered to ensure secrecy, eligibility and
verifiability of online voting. Nonetheless, the over-
whelming majority of current online voting protocols,
as we detail hereafter, are either lacking properties, so
that trust in authorities to carry out essential tasks must
be assumed, or use advanced cryptography, which im-
poses trust in technology as expert knowledge cannot
be implied.
One can distinguish online voting protocols by the
following concepts to ensure both secrecy of the ballot
and eligibility (Lambrinoudakis et al., 2003):
ICISSP 2017 - 3rd International Conference on Information Systems Security and Privacy
500

Trusted Authorities. A very basic approach is to as-
sume trust in all or a subset of the authorities. Voters
transmit their ballot to the authorities using an au-
thenticated channel that allows to verify the eligibility.
Authorities are trusted to keep ballots confidential and
to produce the correct tally.
Anonymous Voting. Using an authenticated chan-
nel, voters acquire from one authority an eligibility
token, e.g. using blind signatures (Chaum, 1983), that
cannot be linked to the voter’s identity, but allows to
verify its eligibility. Then, voters send both ballot and
token through an anonymous channel to the authority.
Technological trust is assumed in the secrecy ensured
by the token. Authorities are trusted to produce the
correct tally.
Random Perturbation. Voters send encrypted bal-
lots to a group of authorities that shuffle one after
each other the set of all ballots. Shuffling can be re-
alised using a secure multi-party computation called
Mix-Nets (Chaum, 1981). This way, ballots cannot
be linked to voters if at least one authority is honest.
Afterwards, ballots are decrypted to compute the tally.
Technological trust and trust in at least one authority
is assumed.
Homomorphic Encryption. With homomorphic
encryption, encrypted ballots are tallied and decrypted
only afterwards (Benaloh, 1987). To prevent early
decryption, (k, n) -threshold cryptography (Pedersen,
1991) is used, which requires the cooperation of k out
of n authorities. The use of cryptography implies tech-
nological trust and trust in authorities to the extent that
less than k out of n authorities are dishonest.
Balancing Verifiability and Secrecy of the Ballot.
Online voting protocols offering end-to-end verifiabil-
ity (Benaloh et al., 2014) allow voters to verify the on-
line voting outcome using cryptographic proofs. How-
ever, the very nature of the mentioned cryptographic
protocols prevents to have both universal verifiability
of the voting outcome and unconditional secrecy of the
ballot (Chevallier-Mames et al., 2010). Eventually, au-
thorities have to be trusted to either respect the secrecy
of the ballot or deliver the correct voting outcome. For
a trustworthy voting, it is reasonable to let all voters
choose their trusted authorities. Hence, the number of
authorities is in the order of voters, which is infeasi-
ble for large scale elections with protocols based on
the presented cryptographic concepts, because of an
amount of required resources polynomial (or worse) in
the number of authorities. As the distribution of pow-
ers in retrospect seems to be problematic, we consider
in the next sections dedicated distributed protocols.
4 DISTRIBUTED PROTOCOLS
Without consensus on trusted authorities, it is reason-
able to omit authorities altogether if possible and as-
sume instead equipotency of all voters.
Bitcoin (Nakamoto, 2008) demonstrates the feasi-
bility to find such protocols without trusted authority.
It establishes an electronic currency without inherent
value, prevents its duplication, thus, double spending,
and allows for fast online transactions between peers
from many internet-enabled devices. Therefore, the
protocol assumes that the majority of computing re-
sources is controlled by honest peers. Technically,
Bitcoin can be interpreted as an approach to the situa-
tion in the past, when traders used mostly currencies
of inherent value such as gold, and no trust in online
banking systems or authorities like central banks were
assumed (Perez-Marco, 2016). Hence, after technolog-
ical progress allowed a shift from distributed offline
to centralised online systems, Bitcoin presents a dis-
tributed online alternative, c.f. Fig. 1 (c). A similar
analogy is given with BitTorrent (Cohen, 2008) that
allows its peers to share their resources to provide in-
formation (files) online, when before central online
servers had to be used. The notion of peer empower-
ment/democracy in both Bitcoin and BitTorrent offers
inspiration for the development of novel online vot-
ing protocols and is further detailed in the following
section.
Figure 1: (a) centralised, (b) decentralised, (c) distributed
systems. Points represent peers and lines interaction between
peers. In (a), strong specialisation and hierarchy is depicted
as one sole peer carries out a distinct role. The hierarchy
becomes more flat in (b) as more peers serves as intermedi-
aries. In (c), peers are equipotent and interact with any set
of peers, e.g. within a given distance.
Distributed Protocols at the Rescue for Trustworthy Online Voting
501

5 EMPOWERMENT OF VOTERS
In his essay “Authoritarian and Democratic Technics”,
Mumford (Mumford, 1964) explained the arising con-
flict if technology for democratic purposes is based
on authorities. Indeed, protocols that omit distinct
authorities and instead make provisions for equally
privileged, equipotent voters sharing the same respon-
sibilities, seem to better reflect the basic democratic
concept of equally powerful voters. We assume further
a distributed online voting protocol in which voters are
represented as equipotent peers.
In BitTorrent and Bitcoin, peers cooperate, because
they share a common goal. Peers are providers and
consumers at the same time. Applied to online voting,
we find a constellation similar to paper-based voting
where voters serve as voting officers to run the voting
station and carry out the supervision.
Even though not all tasks can be carried out by
everyone at the same time, equipotent peers can re-
place each other easily. All peers are responsible to
enforce the protocol policy, while byzantine peers with
inconsistent behaviour are often tolerated to a certain
degree. These properties contribute to the robustness
of the protocol as there is no weakest link or bottleneck.
Therefore, distributed protocols offer great potential
for resilience against Distributed Denial of Service
(DDoS) attacks.
The peers joining a distributed system, contribute
with their own resources, e.g. communication capacity,
memory and computation power. The global resources
grow and diminish with peers joining or leaving the
system offering potential for great scalability. Further,
distributed protocols allow for ephemeral databases
that vanishes entirely when all peers have left the sys-
tem, offering new avenues for applications with sensi-
tive data such as voting. In the case of centralised on-
line voting protocols, ballots are most often encrypted,
but there might be potential for a malicious decryption
at some point in the future, if the implementation of
cryptographic routines turns out to be flawed, secret
keys leak or computing power got sufficiently cheap
to brute-force the encryption.
As every peer has only partial knowledge of the
global information, any unintentional or intentional
disclosure is locally bounded. The impact of an attack,
and thus its incentive, is reduced. In contrast, a disclo-
sure by the authorities of centralised online voting can
impact the secrecy of all casted ballots.
6 TOWARDS ONLINE VOTING
WITHOUT AUTHORITIES
As presented in Sec. 3, cryptographic algorithms al-
low to limit the power of authorities in online voting
protocols. Note, that there is a trade-off. Less trust in
authorities is assumed if authorities are less powerful,
but as the protocol complexity increases, more tech-
nological trust is required. Using Anonymous Voting
for example, voters do not have to present their bal-
lot in clear, but have to trust in the properties of the
eligibility token.
Further, online voting protocols employing many
authorities might assign authorities either equal roles
like in Random Perturbation or Homomorphic Encryp-
tion where authorities carry out the same tasks, or
different roles. In Anonymous Voting, one authority
ensures the eligibility of voters while the other aggre-
gates all ballots and produces the tally. If all authorities
are equipotent and their number can match the number
of voters allowing for an identification between au-
thorities and voters, the protocol becomes essentially
distributed. In between, there is room for different
kinds of partially distributed protocols that we want
to characterise as follows. Note, that the registration
phase shall not be considered in this paper.
Degree of Specialisation. ranging from equipotent
voters with no specialisation to authorities with
dedicated powers
Topology. ranging from centralised over decen-
tralised to distributed topologies, c.f. Fig. 1
Phase. Authorities can intervene either not at all, only
in few or in all phases (not distributed).
A protocol shall be called fully distributed if the
topology is distributed and voters are equipotent during
all phases but the registration.
Note, that we consider large scale elections for our
analysis. First, we want to qualify paper-based voting
as presented in Sec. 2. There are responsible voting
officers, who can principally exchanged as no special
knowledge is required. If we accept that every voter
can become spontaneously voting officer, the protocol
is actually fully distributed during all phases.
Helios. One of the few published, well-studied on-
line voting protocols with unconditional end-to-end
verifiability is Helios (Adida, 2008). While the orig-
inal version is based on Random Pertubation (Mix-
Nets), the version available online
1
uses Homomor-
phic Encryption. In both cases trusted authorities are
1
https://vote.heliosvoting.org/faq
ICISSP 2017 - 3rd International Conference on Information Systems Security and Privacy
502

assumed for threshold decryption requiring communi-
cation costs polynomial in the number of authorities.
Hence, the number of authorities must be small. Dur-
ing the aggregation, ballots are sent to the authorities
for tallying, which corresponds to a centralised topol-
ogy. The final step of end-to-end verification is the
only distributed phase, because it can be carried out
independently by all voters once the authorities have
published the required material.
While Helios is as such an online voting proto-
col employing a central web server to receive ballots
and produce the tally, other protocols do not require
such a server as they omit an authority. A selection is
presented hereafter.
Secure Multiparty Computations. The aim of Se-
cure Multiparty Computations (SMC) is to compute
collectively a joint function over the private inputs of
all participants. The correctness and secrecy proper-
ties rely on cryptography (Yao, 1982). It seems to be
an appropriate technique to compute the tally from
the individual, secret ballots. However, several issues
render an implementation of a decentralised voting
protocol based on this scheme difficult. As (Gambs
et al., 2011) points out, the communication complex-
ity for n participants is O

n
2

, or in the case of the
existence of a trusted party, O (n) . Both render the
scheme impractical for large-scale distributed online
voting. Though, SMC is suited for boardroom voting
protocols with only few voters.
Furthermore, the employed cryptography is com-
putationally extensive and provides often only compu-
tational instead of information-theoretic security.
Scalable and Secure Aggregation Protocol. An in-
termediate solution between a centralised online voting
protocol based on cryptography and an aggregation by
the voters is given with Scalable and Secure Aggrega-
tion (SPP) (Gambs et al., 2011). Voters are grouped
using a chord overlay into clusters of equal size in or-
der to partition potential dishonest voters. The clusters
are then arranged in a binary tree structure (Fig. 2 (b)).
Voters assigned to the root cluster have to create a key
pair for homomorphic public-key cryptography. Thus,
a (k, n) -threshold decryption key pair is jointly created
using a distributed key generation protocol. While the
private key parts are distributed among the members
of the root cluster, the public key is communicated to
all child clusters in the tree.
Every voter encrypts its ballot and adds a non-
interactive zero-knowledge-proof to back the validity
of its vote. Encrypted ballots are gathered from vot-
ers in the same cluster to compute an intermediate
aggregate for the cluster. From the tree leaves, aggre-
(a) DPol
(b) SPP
(c) SMC
(d) Blockchain
Figure 2: Topology of distributed voting protocols. (a) DPol
and (b) SPP have a higher degree of hierarchy than (c) SMC
and (d) blockchain-based protocols due to partition of voters
in clusters. This way, the number of exchanged messages
can be reduced at the cost of less equipotent voters with less
flexible roles. Unstructured SMC- and blockchain-based
protocols use a distributed topology allowing for equipotent
voters.
gates are passed to all members of the parent cluster,
who compute first the sub-tree aggregate taking into
account the own aggregate and those of its child, and
pass the result to all members of the parent cluster. By
majority rule, voters decide in case of diverging results
which aggregate has to be used for the computation.
At some point, the root cluster will possess the
encrypted final tally of all ballots. A union of k vot-
ers will carry out the joint decryption algorithm to
compute the final tally that is subsequently propagated
down the tree to all voters.
Even though all voters are involved in the aggrega-
tion procedure, the parity of knowledge is not given.
The voters in the root cluster correspond effectively
to randomly determined, trusted voting officers in a
centralised protocol, that cannot be flexibly exchanged
after the key pair generation.
Decentralised Polling. Another technique to realise
distributed online voting is based on secret sharing
schemes. A corresponding protocol known as Decen-
tralised Polling (DPol) is described in (Guerraoui et al.,
2012). n voters are grouped to clusters of size
√
n . The
clusters form a ring, so that each cluster has one pre-
ceding and one succeeding cluster (Fig. 2 (a)). Every
voter gets accorded 2k + 1 recipient voters from the
succeeding cluster and is itself recipient to 2k + 1 vot-
ers from the preceding cluster. k is a privacy parameter.
A ballot for a particular option from a set of size d is
represented by a vector in {0, 1}
d
. The voter issues
then 2k + 1 vectors, k + 1 towards its choice and k for
others. The vectors are distributed among the receivers.
In the next step, received vectors are summed up and
the result is exchanged with other voters of the same
cluster in order to compute the tally for the preced-
ing cluster. The tallies are then communicated to the
succeeding clusters in the ring until every cluster is in
possession of all the cluster tallies such that the final
tally can be computed by every voter.
Distributed Protocols at the Rescue for Trustworthy Online Voting
503

Table 1: Quality of distribution of selected online voting protocols.
Protocol Degree of Specialisation Topology Distributed Phases
Paper-based Voting none (flexible) distributed all
Helios, (Adida, 2008) selected authorities centralised verification
SPP, (Gambs et al., 2011) random authorities structured, tree aggregation
DPol, (Guerraoui et al., 2012) none structured, ring all
Blockchain-based Voting none (flexible) distributed all
It is remarkable, that this scheme provides secrecy
of the ballot without the employment of cryptogra-
phy. The protocol authors describe means to determine
dishonest voters with high probability without false-
positives and tag them accordingly, e.g. in a public
social network profile.
Few extensions have been proposed, among them
EPol (Hoang and Imine, 2015), that generalises the
DPol voting system in such a manner, that the actual
social graph structure (with some assumptions) can be
used and a ring social net overlay and a perfect square
voter number is not a prerequisite anymore.
Both DPol and EPol provide for equipotent voters.
The aggregation is a joint effort in which all voters are
involved. Every voter computes the final tally and then
the voting result. Similar to the SPP protocol, interme-
diate aggregates are employed to keep the information
on individual ballots local in the overlay.
Blockchain-based Voting Systems. Online voting
based on Bitcoin technology, namely the global con-
sensus algorithm given by its blockchain, is eagerly
anticipated by some groups. Various prototypes and
commercial solutions are or have been developed
2
.
However, the actual protocols are either lacking essen-
tial properties or remain obscure. Scientific results are
very sparse. Zhao and Chan (Zhao and Chan, 2015)
present a protocol for a binary vote that requires a
monetary deposit and a funding of the winner by all
voters. Transactions to the winner and voter payback is
controlled due to contracts enforced by the distributed
network which limits the flexibility of the ballot.
To the author’s knowledge, most other approaches
to online voting using Bitcoin are based on so-called
coloured coins that allow to associate digital assets
to Bitcoin addresses. Consequently, asset ownership
can be traded like the Bitcoin currency and (pseudony-
mous) ownership is publicly verifiable by following
the previous asset transactions.
To construct an online voting protocol, every voter
must initially own a coloured coin representing its eli-
gibility. Those coins are then transferred to a destina-
2
https://github.com/domschiener/publicvotes,
http://votem.com, http://www.bitcongress.org,
http://followmyvote.com, http://cryptovoter.com,
http://votosocial.github.io
tion that corresponds to e.g. a candidate. Transactions
are publicly verifiable, so that aggregation and evalu-
ation can be carried out by every voter. Though, the
publicity of all transactions endangers the secrecy of
the ballot, because coins can be linked back to the
voter that has been identified during the registration
phase to receive its coin.
Different protocols have been proposed to provide
anonymous Bitcoin transactions (Miers et al., 2013;
Ibrahim, 2017) that are considered to ensure secrecy
of the ballot in blockchain-based online voting. Also
blind signatures may permit to distribute coins anony-
mously to voters. In that case, the protocol approaches
the Anonymous Voting concept (c.f. Sec. 3). The au-
thority carrying out the aggregation is hereby replaced
by the distributed blockchain that serves as a public
add-only bulletin board to log casted ballots. Conse-
quently, tallying and verification can be carried out by
every voter. The distributed topology is inherited from
Bitcoin which uses gossiping to spread transactions
(Fig. 2 (d)). Transactions are then gathered into blocks
by voters or third parties that seek to confirm transac-
tions. Every voter can as its own discretion engage in
the confirmation procedure. There is no specialisation
of voters.
It turns out that blockchain-based and paper-based
voting are on par with respect to the notions of distri-
bution and qualify both as fully distributed, c.f. Tab. 1.
7 CONCLUSION
Major votings in 2016, e.g. the Brexit referendum or
the US presidential elections, demonstrated the impor-
tance of a high voter turnout for the legitimacy of the
outcome, especially in the case of tight outcomes.
While online voting is generally considered with
much hesitation, advances in technology are eroding
the security of paper-based voting. Coercion-freeness,
in the past a major argument for on-site ballot casting,
is at stake due to omnipresent smart phone cameras.
Exit polls on social media allow voters casting their
ballot very late a more informed choice, which harms
the fairness. More and more voters use early postal
voting sacrificing thus their means of verification and
the potential to change their vote last minute. Mean-
ICISSP 2017 - 3rd International Conference on Information Systems Security and Privacy
504

while, many online voting protocols seek to achieve
those security properties that paper-based voting with
optional postal voting can ensure less and less.
In this situation, distributed online voting offers a
promising perspective. It does not assume a trusted
authority and the integrity of the voting is enforced
by the voters themselves. Without a weakest link,
votings are difficult to interrupt. The damage in case
of security breaches is locally bounded thanks to the
distribution of data. Like in all online voting protocols,
voting becomes more convenient, especially as ballots
can be casted from remote. We acknowledge that still
trust in technology or expert knowledge is assumed
and leave it as an open issue.
So far, only few distributed online voting protocols
have been proposed and even less are fully distributed.
We hope to see more proposals in the future and plan
to contribute to this subject with a novel fully dis-
tributed protocol. This work in progress follows the
Anonymous Voting concept and uses techniques from
BitTorrent to create a voter overlay network and from
Bitcoin to ensure verifiability. Similar to DPol, secrecy
is provided by a particular sharing scheme instead of
cryptography. To achieve logarithmique complexity, it
is based like SPP on a tree overlay network. Unlike in
SPP, no decryption step is needed. Hence, all voters
are equipotent.
ACKNOWLEDGEMENTS
The authors wish to thank Stéphane Frénot, Damien
Reimert and Aurélien Faravelon for fruitful discus-
sions on distributed voting protocols.
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