A Practical Electronic Voting Protocol Using Threshold Schemes

Abstract

This paper presents a novel secret voting scheme which fully conforms to the requirements of large scale elections. The participants in the scheme are voters, candidates, an administrator, and a counter. The scheme uses threshold encryption to preserve the privacy and accuracy of the votes against dishonesty of voters, candidates, the administrator, and the counter. It also ensures verifiability, fairness, and soundness of the voting process and hence neither administrator nor candidates, or the counter is capable of producing false tally, affecting the voting result, or corrupting/disrupting the election. A Practical Electronic Voting Protocol Using Threshold Schemes 1 Introduction The development of cryptographic techniques allow us to "computerize" many areas of human activities. Voting is an important human activity in a democratic society. The problem of providing a secure system which ensures privacy of the voters and accuracy of the votes, and is suitable for application in l...

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2. Registration.
3. Voting.
1. Preparation.
4 Opening.
It consists of two steps:
The signed ballot x is sent to all N candidates anonymously by voter Vi.
i
a.
c.
a.
i
b.
i
Voters send their encryption key to the counter anonymously.
Counter opens votes and counts them and announces the result.
b.
b.
Each candidate computes his/her partial cryptogram share on the signed
The counter computes all t of N combinations c and w to get the ballot
and z . If the majority of the ballot computed is the same and psuedo
identity z is valid then a roster of valid ballot is made and published.
i
i
jj
i
ballots and decrypted psuedo identities and then (c , w ) to the counter.
j
j
A trusted party generates N secret keys of the threshold encryption scheme
distributes the partial keys to the candidates and a corresponding key K to the
counter.
The voters’ pseudo identities decrypted by K and sent via an untraceable channel.
-1
-1
a. Voter V creates x and makes the message e
i
, that hidden ballot,
and sends it to A for A’s blind signature.
Administrator A signs the message e and sends the signature to the voter.

1
executes phase
x=B(v,k)
Ballot
prepares
VOTER: Administrator
executes phase
2
list of <ID,e,s>
registered voters
Publish m as a number of the
Broadcast channel
d=S (e) if a voter not already applied and eligible
A
<ID, e, s > where s =S(e) and e= X(x, r)

VOTER
COUNTER
CANDIDATES
VOTER:
:
Each candidate
C
C
C
C
1
2
N-1
N
i i
checks y A’
signature on ballot x
i
i
j
candidate.
COUNTER:
Anonymous channel
Broadcast channel
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j
(z ,x y )
(z ,x y )
(x , y ).c .w
(x , y ).c .w
(z ,x y )
ii
i
ii
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i
(z ,x y )
i i i
i i
i i
(x , y ).c .w
i i
i
1
1
2 2
N N
(x ,y )c
N-1
.w
N-1
(x , y ).c .w is sent to the counter.
i i j
j
(l , x , y )
i i
i
i
THEN it is valid
sends(z ,x ,y ) IF A’signature y =R (d ,r )
ELSE publish(x , y )
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’
’
’
’
’
’
IF signature is valid THEN
’
IF t out of N Combination of c
are equal and z is valid THEN
i i A i i
i
ELSE piblishes (z ,x y )
i i
Finally m
; the number of accepted ballots, is published by the

VOTER
COUNTER
j
Anonymous channel
opens ballot x
counts votes and publishes
the result
i
C
i-th
IF t out of N m = m (<= m ) and(x , y )
A
i
i
is in the list THEN send (l, k )
i