Secret balloting through the Internet is not only a technical
evolution, but also a social activity realizable in the near
future. We consider four phases necessary to complete the
evolving progress: (1) theoretical research, (2) development and
implementation of prototype systems, (3) trial experiments on
pilot systems, and (4) promotion toward widespread acceptance
from the society. In this dissertation, we refine a theoretic
protocol, implement a prototype system based on the revised
protocol, and conducIn the effort of theoretic improvement, we
revise the order of Mixer''s procedures in Hwang''s protocol [36]
to enhance privacy of ballots. In addition, we design in details
authorities'' acknowledgments and evidences. Therefore, through
the extension of Hwang''s protocol, a voter can protect his legal
right of keeping his ballot private and verifying his vote on
the one hand; on the other, authorities can prevent themselves
from malfeasant accusation. In the effort of system
implementation, we develop a secret balloting system for group
decision environment. To investigate user attitude toward a
secret balloting system, we conduct a questionnaire with the
prototype system and specify students of Institute of
Information Management in NCTU as our sample. From this
investigation we arrive at a conclusion that for users with more
experiences of using computers, a secret balloting system
provides as much anonymity as does a questionnaire.A limit of
our current prototype system is that it does not provide the
functions of receipt-free and universal verifiability. As a
result, it is not suitable for a large-scale election. The
experimental result proves our system operational, so we suggest
that the system be used in a group decision environment.In our
solution, voters can prove their votes to the court, and accuse
the cheating official. Now, we don''t have any acceptable
solution to receipt-free and universal verifiability, we would
study more related literatures and try to propose some
solutions. When we can propose a solution satisfied both
receipt-free and universal verifiability. We also would like to
revise our secret balloting system for a large-scale election.