Electronic voting technology can include punch cards, optical scan voting systems and specialized voting kiosks (including self-contained Direct-recording electronic (DRE) voting systems). It can also involve transmission of ballots and votes via telephones, private computer networks, or the Internet.
Electronic voting technology can speed the counting of ballots and can provide improved accessibility for disabled voters. However, there has been contention, especially in the United States, that electronic voting, especially DRE voting, can facilitate electoral fraud.
There are also hybrid systems that include an electronic ballot marking device (usually a touch screen system similar to a DRE) or other assistive technology to print a voter-verifiable paper ballot, then use a separate machine for electronic tabulation.
Most recently, these systems can include an Electronic Ballot Marker (EBM), that allow voters to make their selections using an electronic input device, usually a touch screen system similar to a DRE. Systems including a ballot marking device can incorporate different forms of assistive technology.
A direct-recording electronic (DRE) voting machine records votes by means of a ballot display provided with mechanical or electro-optical components that can be activated by the voter (typically buttons or a touchscreen); that processes data with computer software; and that records voting data and ballot images in memory components. After the election it produces a tabulation of the voting data stored in a removable memory component and as printed copy. The system may also provide a means for transmitting individual ballots or vote totals to a central location for consolidating and reporting results from precincts at the central location. These systems use a precinct count method that tabulates ballots at the polling place. They typically tabulate ballots as they are cast and print the results after the close of polling.
In 2002, in the United States, the Help America Vote Act mandated that one handicapped accessible voting system be provided per polling place, which most jurisdictions have chosen to satisfy with the use of DRE voting machines, some switching entirely over to DRE. In 2004, 28.9% of the registered voters in the United States used some type of direct recording electronic voting system, up from 7.7% in 1996.
Public network DRE voting system can utilize either precinct count or central count method. The central count method tabulates ballots from multiple precincts at a central location.
Internet voting can use remote locations (voting from any Internet capable computer) or can use traditional polling locations with voting booths consisting of Internet connected voting systems.
Corporations and organizations routinely use Internet voting to elect officers and Board members and for other proxy elections. Internet voting systems have been used privately in many modern nations and publicly in the United States, the UK, Ireland, Switzerland and Estonia. In Switzerland, where it is already an established part of local referendums, voters get their passwords to access the ballot through the postal service. Most voters in Estonia can cast their vote in local and parliamentary elections, if they want to, via the Internet, as most of those on the electoral roll have access to an e-voting system, the largest run by any European Union country. It has been made possible because most Estonians carry a national identity card equipped with a computer-readable microchip and it is these cards which they use to get access to the online ballot. All a voter needs is a computer, an electronic card reader, their ID card and its PIN, and they can vote from anywhere in the world. Estonian e-votes can only be cast during the days of advance voting. On election day itself people have to go to polling stations and fill in a paper ballot.
Electronic voting systems may offer advantages compared to other voting techniques. An electronic voting system can be involved in any one of a number of steps in the setup, distributing, voting, collecting, and counting of ballots, and thus may or may not introduce advantages into any of these steps. Potential disadvantages exist as well including the potential for flaws or weakness in any electronic component.
Charles Stewart of the Massachusetts Institute of Technology estimates that 1 million more ballots were counted in 2004 than in 2000 because electronic voting machines detected votes that paper-based machines would have missed.
In May 2004 the U.S. Government Accountability Office released a report titled "Electronic Voting Offers Opportunities and Presents Challenges, analyzing both the benefits and concerns created by electronic voting. A second report was released in September 2005 detailing some of the concerns with electronic voting, and ongoing improvements, titled "Federal Efforts to Improve Security and Reliability of Electronic Voting Systems Are Under Way, but Key Activities Need to Be Completed.
It has been demonstrated that as voting systems become more complex and include software, different methods of election fraud become possible. Others also challenge the use of electronic voting from a theoretical point of view, arguing that humans are not equipped for verifying operations occurring within an electronic machine and that because people cannot verify these operations, the operations cannot be trusted. Furthermore, some computing experts have argued for the broader notion that people cannot trust any programming they did not author.
Under a secret ballot system, there is no known input, nor any expected output with which to compare electoral results. Hence, electronic electoral results and thus the accuracy, honesty and security of the entire electronic system cannot be verified by humans..
Critics of electronic voting, including security analyst Bruce Schneier, note that "computer security experts are unanimous on what to do (some voting experts disagree, but it is the computer security experts who need to be listened to; the problems here are with the computer, not with the fact that the computer is being used in a voting application)...DRE machines must have a voter-verifiable paper audit trails... Software used on DRE machines must be open to public scrutiny to ensure the accuracy of the voting system. Verifiable ballots are necessary because computers can and do malfunction, and because voting machines can be compromised.
Critics argue the need for extra ballots in any language can be mitigated by providing a process to print ballots at voting locations. They argue further, the cost of software validation, compiler trust validation, installation validation, delivery validation and validation of other steps related to electronic voting is complex and expensive, thus electronic ballots aren't guaranteed to be less costly than printed ballots.
Organizations such as the Verified Voting Foundation have criticized the accessibility of electronic voting machines and advocate alternatives. Some disabled voters (including the visually impaired) could use a tactile ballot, a ballot system using physical markers to indicate where a mark should be made, to vote a secret paper ballot. These ballots can be designed identically to those used by other voters.. However, other disabled voters (including voters with dexterity disabilities) could be unable to use these ballots.
One feature to mitigate such concerns could be to allow a voter to prove how they voted, with some form of electronic receipt, signed by the voting authority using digital signatures. This feature can conclusively prove the accuracy of the tally, but any verification system that cannot guarantee the anonymity of voter's choice, can enable voter intimidation or vote selling.
Some cryptographic solutions aim to allow the voter to verify their vote personally, but not to a third party. One such way would be to provide the voter with a digitally signed receipt of their vote as well as receipts of other randomly selected votes. This would allow only the voter to identify her vote, but not be able to prove her vote to anyone else. Furthermore, each vote could be tagged with a randomly generated voting session id, which would allow the voter to check that the vote was recorded correctly in a public audit trail of the ballot.
A fundamental challenge with any voting machine is assuring the votes were recorded as cast and tabulated as recorded. Non-document ballot voting systems can have a greater burden of proof. This is often solved with an independently auditable system, sometimes called an Independent Verification, that can also be used in recounts or audits. These systems can include the ability for voters to verify how their votes were cast or further to verify how their votes were tabulated.
A discussion draft argued by researchers at the National Institute of Standards and Technology (NIST) states, "Simply put, the DRE architecture’s inability to provide for independent audits of its electronic records makes it a poor choice for an environment in which detecting errors and fraud is important. The report does not represent the official position of NIST, and misinterpretations of the report has led NIST to explain that "Some statements in the report have been misinterpreted. The draft report includes statements from election officials, voting system vendors, computer scientists and other experts in the field about what is potentially possible in terms of attacks on DREs. However, these statements are not report conclusions.
Various technologies can be used to assure voters that their vote was cast correctly, detect possible fraud or malfunction, and to provide a means to audit the original machine. Some systems include technologies such as cryptography (visual or mathematical), paper (kept by the voter or only verified), audio verification, and dual recording or witness systems (other than with paper).
Dr. Rebecca Mercuri, the creator of the Voter Verified Paper Audit Trail (VVPAT) concept (as described in her Ph.D. dissertation in October 2000 on the basic voter verifiable ballot system), proposes to answer the auditability question by having the voting machine print a paper ballot or other paper facsimile that can be visually verified by the voter before being entered into a secure location. Subsequently, this is sometimes referred to as the "Mercuri method." To be truly voter-verified, the record itself must be verified by the voter and able to be done without assistance, such as visually or audibly. If the voter must use a bar-code scanner or other electronic device to verify, then the record is not truly voter-verifiable, since it is actually the electronic device that is verifying the record for the voter. VVPAT is the form of Independent Verification most commonly found in elections in the United States.
End-to-end auditable voting systems can provide the voter with a receipt she can take home. This receipt does not allow her to prove to others how she voted, but it does allow her to verify that her vote is included in the tally, all votes were cast by valid voters, and the results are tabulated correctly. End-to-end (E2E) systems include Punchscan, ThreeBallot and Prêt à Voter. Scantegrity is an add-on that extends current optical scan voting systems with an E2E layer. These systems have not yet been used in U.S. elections.
Systems that allow the voter to prove how they voted are never used in U.S. public elections, and are outlawed by most state constitutions. The primary concerns with this solution are voter intimidation and vote selling.
An audit system can be used in measured random recounts to detect possible malfunction or fraud. With the VVPAT method, the paper ballot is often treated as the official ballot of record. In this scenario, the ballot is primary and the electronic records are used only for an initial count. In any subsequent recounts or challenges, the paper, not the electronic ballot, would be used for tabulation. Whenever a paper record serves as the legal ballot, that system will be subject to the same benefits and concerns as any paper ballot system.
To successfully audit any voting machine, a strict chain of custody is required.
The solution was first demonstrated (New York City, March 2001) and used (Sacramento,CA 2002) by AVANTE International Technology, Inc.. In 2004 Nevada was the first state to successfully implement a DRE voting system that printed an electronic record. The $9.3 million voting system provided by Sequoia Voting Systems included more than 2,600 AVC EDGE touchscreen DREs equipped with the VeriVote VVPAT component. The new systems, implemented under the direction of then Secretary of State Dean Heller replaced largely punch card voting systems and were chosen after feedback was solicited from the community through town hall meetings and input solicited from the Nevada Gaming Control Board.
One method to any error with voting machines is parallel testing, which are conducted on the Election Day with randomly picked machines. The ACM published a study showing that, to change the outcome of the 2000 U.S. Presidential election, only 2 votes in each precinct would have needed to been changed.
Benefits can include reduced tabulation times and an increase of participation (voter turnout), particularly through the use of Internet voting.
Those in opposition suggest alternate vote counting systems, citing Switzerland (as well as many other countries), which uses paper ballots exclusively, suggesting that electronic voting is not the only means to get a rapid count of votes. A country of a little over 7 million people, Switzerland publishes a definitive ballot count in about six hours. In villages, the ballots are even counted manually.
Critics also note that it becomes difficult or impossible to verify the identity of a voter remotely, and that the introduction of public networks become more vulnerable and complex.
It is not yet clear whether the total cost of ownership with electronic voting is lower than other systems.

Some groups such as the Open Voting Consortium believe that to restore voter confidence and to reduce the potential for fraud, all electronic voting systems must be completely available to public scrutiny.
Legislation has been introduced in the United State's Congress regarding electronic voting including the Nelson-Whitehouse bill. This bill would appropriate as much as 1 billion dollars to fund states replacement of touch screen systems with optical scan voting system. The legislation also address requiring audits of 3% of precincts in all federal elections. It also mandates some form paper trail audits for all electronic voting machines by the year 2012 on any type of voting technology.
Another bill, HR.811 (The Voter Confidence and Increased Accessibility Act of 2007), proposed by Representative Rush D. Holt, Jr., a Democrat from New Jersey, would act as an amendment to the Help America Vote Act of 2002 and require electronic voting machines to produce a paper audit trail for every vote. The U.S. Senate companion bill version introduced by Senator Bill Nelson from Florida on November 1, 2007, necessitates the Director of the National Institute of Standards and Technology to continue researching and to provide methods of paper ballot voting for those with disabilities, those who do not primarily speak English, and those who do not have a high literacy rating. Also, it requires states to provide the federal office with audit reports from the hand counting of the voter verified paper ballots. Currently, this bill has been turned over to the United States Senate Committee on Rules and Administration and a vote date has not been set.
During 2008 Congressman Holt, because of an increasing concern regarding the insecurities surrounding the use of electronic voting technology, has submitted additional bills to Congress regarding the future of electronic voting. One, called the "Emergency Assistance for Secure Elections Act of 2008" (HR5036), states that the General Services Administration will reimburse states for the extra costs of providing paper ballots to citizens, and the costs needed to hire people to count them. This bill was introduced to the House on January 17, 2008 . This bill estimates that $500 million will be given to cover costs of the reconversion to paper ballots; $100 million given to pay the voting auditors; $30 million given to pay the hand counters. This bill provides the public with the choice to vote manually if they do not trust the electronic voting machines. . A voting date has not yet been determined.
In Runoff, a 2007 novel by Mark Coggins, a surprising showing by the Green Party candidate in a San Francisco Mayoral election forces a runoff between him and the highly favored establishment candidate--a plot line that closely parallels the actual results of the 2003 election. When the private-eye protagonist of the book investigates at the behest of a powerful Chinatown businesswoman, he determines that the outcome was rigged by someone who defeated the security on the city's newly installed e-voting system.
"Hacking Democracy" is a 2006 documentary film shown on HBO. Filmed over three years, it documents American citizens investigating anomalies and irregularities with electronic voting systems that occurred during America's 2000 and 2004 elections, especially in Volusia County, Florida. The film investigates the flawed integrity of electronic voting machines, particularly those made by Diebold Election Systems and culminates in the hacking of a Diebold election system in Leon County, Florida.
The 2008 film Uncounted documents the alleged problems caused by electronic voting machines and their software manufactured by Diebold.