An electronic voting system (on-line voting, internet voting) is an election system which uses electronic ballot that would allow voters to transmit their secure and secret voted ballot to election officials over the internet . With the prosperity of internet over the years, inventers start to make the use of electronic voting in order to make the voting process more convenient and raise the participation of the civic. From now on, engineers have repeatedly created new technology to improve the feasibility of electronic voting system.
The advocate of electronic voting claims that the convenience, mobility, tally speed, less cost, and flexibility are the main advantages. Following are the descriptions of the advantages. Convenience: With the well-designed software and system, the voters can simply use his voting equipment with the minimal time and skill to finish the voting process . Mobility: Voters can cast their votes at a specific polling place, home, or any place in which they can get access to the internet. People can even use the mobile device such as cell phone or PDA to vote. There is no restriction on the location . Tally Speed:  Once the voting time is over, the computer can immediately calculate the result of the election. It is much faster than the traditional ballot counting method operated by people. Less Cost:  Compared to paper ballot voting, electronic voting saves money from reducing the personnel expense, expense for location management and administration fee, etc. In the beginning, the investment expense of building up the electronic voting system would be very high. But after the system is built up, the total expense would be reduced to be much lower than paper ballot voting. Flexibility: Electronic voting system can be designed to support a variety of ballot question formats . It can be used to collect public opinions or election. Voter participation: With convenience and mobility of the system, it would motivate people who are not interested in voting or unable to vote originally. It would increase the participation of voters.
Despite the particular advantages to electronic voting system, critics of electronic voting argue about the security issue and the unequal access chance to the internet are the main drawbacks to the system. Inequality problem: It is apparent that the people with low salary might not be able to afford the equipment for electronic voting. And some people who are not able to use the computer facility might lose their privilege in voting. Vulnerable to Security: The security issue is the main drawback of the electronic voting system. So far, there are still many kinds of attacks which are hard to prevent completely. The attacks might be happened from the webpage, network, to the extent of server’s database. Denial of Service attack: A denial of service is characterized by that an attacker prevents legitimate users from using resources. An attacker may attempt to “flood” a network and thus reduce a legitimate user’s bandwidth, prevent access to a service, or disrupt service to a specific system or a user . Now it is very hard to completely avoid this kind of attack. Nevertheless, people can adopt some methods such as “Filtering Routers”, “Disabling IP Broadcast”, “Disabling Unused Services”, and Performing intrusion Detection”  to make the network more secure. Virus: Virus such as Trojan horse would do great damage to the system. The server can be easily protected from the attack of virus by using some specific kinds of operating system. But the client such as personal computers might not secure enough and are easily infected with virus. These viruses might attack computer from the operating system level to the web browser level. It might infringe the secret-ballot and privacy, modify the result without the voter’s acknowledgement, and reduce the justice of the election. If a large number of voters’ computers are attacked by virus, then the election might have to be canceled or re-vote in other time.
4. Basic Requirement A good electronic voting system should meet the following requirement: Authentication : Only the eligible and authorized voters can vote through the system. Accuracy : Every voted ballot should be correctly counted into the final tally within the tolerable extent of error. Integrity: Votes should not be able to be modified, forged or deleted without detection .
Secrecy and Non-Coercion: Only voters know what they vote for. Voters must not be able to prove what they vote for in order to reduce the risk of coercion and vote-buying activity . Audit trail : The system should provide the mechanism for audit trail. Audit trail can help to verify that the votes are accounted correctly in the tally and maintain the security for the system. Uniqueness : Every voter has the same number of the votes. No one can vote more times than others. Transparency : The election process should be transparent to the voters. Voters can clearly understand the mechanism of the electronic voting system and know whether their votes have been correctly counted. It can enhance the public confidence toward electronic voting system. Simplicity: The system should be designed with the friendly and simple user interface for voters to handle well with the minimal effort. It should also meet the need of different people who are disabled, illiterate, etc.
Receipt is a double-edged sword in the electronic voting system. It would raise the voters’ confidence if they can see their votes correctly accounted for the final tally. In contrast, the receipt has been considered to raise the risk of infringing the principle of secret-ballot. Since the voter might use the receipt to prove how they vote, the coercion behavior and vote-buying activity might occur. Receipt-free: To introduce the function of receipt, first let’s talk about the receipt-free mechanism which means that a voter neither obtains nor is able to construct a receipt to prove the content of his vote . Sako and Kilian  use a physical assumption which is untappable channel to apply receipt-free system. Untappable channel is physical apparatus by which only the voter can send a message to a party, and the message is perfectly secret to all other parties . The drawback of receipt-free mechanism is that it is hard to implement untappable channel in the real world. Chaumian secret-ballot receipts : Some new technologies and algorithms have been invented to meet the need of giving receipts to voters without infringing the principle of ballot-secrecy. Chaumian secret-ballot receipts method separates the receipt into two unreadable layers, top layer and bottom layer, with special graphical encryption. Each layer contains the partial and implicit information of the receipt. Only after combining the two layers together, it shows the complete and readable content. The voter can choose to take one of the layers and use this layer to check what he votes for in a specific and secure place. The ballot would be transformed
from the input batch into the output batch. It is called Mix Nets  that the ballots would be shuffled during the process of transferring from the current batch to the next batch in order to keep the ballot-secrecy. It reduces the risk of telling how the outputs correspondent to the inputs from the observers.
6. Voting Places
Voting at polling places  : The department can provide the reliable, no virus, and easy-handled voting machine in the polling places. The voters can be authenticated by the traditional protocol and the technological authentication of voters might not be necessary. It provides the highest security compared to other electronic voting place. Voting at home with voter’s computer : Voters can cast their votes by using their own computers at home. It is hard to prevent the third party’s advertisement appearing on the screen while voting. It is much more difficult to secure the voter’s computer from the attacks of hackers and virus. Voting at anyplace with mobile devices : The voters can use their devices to get access to internet in any place and cast a vote through the electronic voting system. Not only can the laptop be used to vote, the PDA, cell phone, and any other mobile devices might also be used to vote in the future. But there are many harsh problems need to overcome. The security is the most serious problem. It is vital to make sure that the computer and network in which the voters get access is not monitored, intercepted, or tampered by any attackers.
6. Relevant Issue
Voter participation : It is controversial how to increase the participation of the voters by adopting electronic voting system. The main consideration is that some people might be motivated to vote due to the convenience and mobility. But there are still some people who might not be willing to use the electronic voting system. On the other hand, people who are unable to use computer facility, illiterate, and disabled might not be willing to participate the election. Voter Information : The electronic voting web page should provide an objective user interface in order not to influence the voter’s behavior. The electronic voting system would change the tradition voting activity in all aspects. How electronic voting would affect in all aspects of administration? How to educate the voters to use the equipment? How to enforce the law about electronic voting? How to maintain the voting equipment? How to set up the front end web site and the back end database? There are lots of related issues should be taken into research.
In this paper, it illustrates the advantages and disadvantages of the electronic voting system and what are the basic requirements of a good system. In the technology aspect, there are still some attacks which are hard to prevent would infringe the security of the system. Inventors have repeatedly created new technology to the system. In the policy aspects, the government should educate voters to use the voting equipment well and build a transparent mechanism which can raise the public confidence toward the voting system. In the foreseeable future, electronic voting system would influence the election behavior a lot. With good-designed system and policy, people can benefit from the new election method.
 Report of the National Workshop on Internet Voting: Issues and Research Agenda, 2001  “An Electronic Polling Service to Support Public Awareness Using Web Technologies”, Christos Bouras, Nikolaos Katris, Vassilis Triantafillou  “A Survey of Current Secret-Ballot Systems”, David. Chaum  “Distributed Denial of Service Attack”, Felix lau, Stuart H. Rubin, Michael H. Smith Ljiljana Trajkovic  “Receipt-Free Secret-Ballot Elections”, pp.544-553, J. Benaloh and D. Tuinstra,  “Receipt-Free Mix-type Voting Scheme” Proc. of Eurocrypt’95, LNCS 921, Springer-Verlag, pp.393-403, K. Sako, and J. Kilian.  “Secret-Ballot Receipts and Transparent integrity”, David Chaum  “ A Report on the Feasibility of Internet Voting”, California Internet Voting Task Force, 2000  “Making Mix Nets Robust For Electronic Voting By Randomized Partial Checking”,2002, Markus Jakobsson, Ari Juels, and Ronald L. Rivest