1. Introduction
An electronic voting system enables voters to
perform electronic voting over computer network.
Conventionally, a secure e-voting system should satisfy
the following requirements:
(1) Anonymity of voter. No one can identify the
voter of a cast ticket.
(2) Unforgeability of ticket. No one can generate a
forged ticket to cheat the authority.
(3) Perceptibility of double voting. All double
voting tickets will be detected and eliminated
by the authority.
Mu and Varadharajan [1] have proposed an electronic
voting system in 1998. They claimed that their
scheme is suitable for large-scale elections and satisfies
all requirements of a secure e-voting system.
Unfortunately, Lin et al. [2] showed that the Mu and
Varadharajan’s scheme does not provide the perceptibility
of double voting. That is, if a voter votes twice,
the authority cannot detect the double voting tickets.
Lin et al. then proposed a modified scheme to solve
this problem. However, this paper shows that the
authority has the ability to identify the owners of
the cast tickets in the Lin et al.’s scheme. Therefore,
the Lin et al.’s scheme cannot satisfy the requirement