Cryptology ePrint Archive: Report 2011/341
An Improved Internet Voting Protocol
Mehmet Sabir Kiraz and Süleyman Kardaş and Muhammed Ali Bingöl and Fatih Birinci
Abstract: Norway is going to experience an Internet voting scheme in
September 2011 for local governmental elections, targeting a comprehensive Internet voting system in 2017 for national election. This protocol
is strong from several aspects. First of all, it resists against malicious
voter’s computers. Namely, an honest voter will be aware of a malicious
behavior caused by the computer during the entire voting procedure.
However, the security of the protocol depends on the assumption that
the players (organizations) are completely independent and reliable, and
the receipt codes are sent to the voters securely.
In this work, we take a closer look at the Internet voting protocol and
investigate the followings:
– The privacy of voters are compromised if there is a cooperation between the players Ballot Box (BB) and Receipt Generator (RG) since
the private key of Decryption Service (DS) can be obtained by the
two former players. To prevent this possible issue, we propose an
improved protocol without adding additional players.
– To verify the correctness of the overall protocol two additional channels are used where receipt codes are sent to the voters over the
pre-channel (e.g., postal service) and also sent over the post-channel
(e.g., SMS). However, if a voter holds both SMS and the paper of
receipt codes at the same time, he can reveal his/her vote even after
the election. To overcome this issue, we propose a new method where
the SMS is used only as a notiﬁcation message, and an additional
phone call is used for the complete veriﬁcation of the vote.
– The reliability of the Norwegian scheme is based on the correctness
of the receipt codes that are sent to the voters over a secure prechannel. However, if the printed receipt codes are falsely generated
(or falsely printed) or the pre-channel is not completely secure, a
vote can be counted for diﬀerent candidates without any detection.
In order to prevent this problem, in our protocol, the voters also take
a part in the veriﬁcation of the receipt codes before the vote casting
Category / Keywords: Internet voting, Voting privacy, Threshold cryptography, Homomorphic encryption
Date: received 23 Jun 2011, withdrawn 9 Jan 2012
Contact author: m kiraz at uekae tubitak gov tr
Available format(s): (-- withdrawn --)
Version: 20120109:082829 (All versions of this report)
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