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 the 2004 US presidential election 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".
Electronic ballots Electronic voting systems may use
electronic ballot to store votes in
computer memory. Systems which use them exclusively are called DRE voting systems. When electronic ballots are used there is no risk of exhausting the supply of ballots. Additionally, these electronic ballots remove the need for printing of paper ballots, a significant cost. When administering elections in which ballots are offered in multiple languages (in some areas of the United States, public elections are required by the
National Voting Rights Act of 1965), electronic ballots can be programmed to provide ballots in multiple languages for a single machine. The advantage with respect to ballots in different languages appears to be unique to electronic voting. For example,
King County, Washington's demographics require them under U.S. federal election law to provide ballot access in Chinese (Mandarin?). With any type of paper ballot, the county has to decide how many Chinese-language ballots to print, how many to make available at each polling place, etc. Any strategy that can assure that Chinese-language ballots will be available at all polling places is certain, at the very least, to result in a significant number of wasted ballots. (The situation with lever machines would be even worse than with paper: the only apparent way to reliably meet the need would be to set up a Chinese-language lever machine at each polling place, few of which would be used at all.) 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 are not guaranteed to be less costly than printed ballots.
Accessibility Electronic voting machines can be made fully accessible for persons with disabilities. Punched card and optical scan machines are not fully accessible for the blind or visually impaired, and lever machines can be difficult for voters with limited mobility and strength. Electronic machines can use headphones,
sip and puff, foot pedals, joy sticks and other
adaptive technology to provide the necessary
accessibility. 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.
Cryptographic verification The concept of election verifiability through cryptographic solutions has emerged in the academic literature to introduce transparency and trust in electronic voting systems. It allows voters and election observers to verify that votes have been recorded, tallied and declared correctly, in a manner independent from the hardware and software running the election. Three aspects of verifiability are considered: individual, universal, and eligibility. Individual verifiability allows a voter to check that her own vote is included in the election outcome, universal verifiability allows voters or election observers to check that the election outcome corresponds to the votes cast, and eligibility verifiability allows voters and observers to check that each vote in the election outcome was cast by a uniquely registered voter.
Voter intent Electronic voting machines are able to provide immediate feedback to the voter detecting such possible problems as
undervoting and
overvoting which may result in a
spoiled ballot. This immediate feedback can be helpful in successfully determining
voter intent.
Transparency It has been alleged by groups such as the UK-based
Open Rights Group that a lack of testing, inadequate audit procedures, and insufficient attention given to system or process design with electronic voting leaves "elections open to error and
fraud". In 2009, the
Federal Constitutional Court of Germany found that when using voting machines the "verification of the result must be possible by the citizen reliably and without any specialist knowledge of the subject." The
DRE Nedap-computers used till then did not fulfill that requirement. The decision did not ban electronic voting as such, but requires all essential steps in elections to be subject to public examinability. In 2013, The
California Association of Voting Officials was formed to maintain efforts toward publicly owned General Public License open source voting systems
Coercion evidence In 2013, researchers from Europe proposed that the electronic voting systems should be coercion evident. There should be a public evidence of the amount of coercion that took place in a particular elections. An internet voting system called "
Caveat Coercitor" shows how coercion evidence in voting systems can be achieved. 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 DRE voters that their votes were cast correctly, and allow officials to detect possible fraud or malfunction, and to provide a means to audit the tabulated results. Some systems include technologies such as cryptography (visual or mathematical), paper (kept by the voter or verified and left with election officials), 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 and other countries such as Venezuela.
End-to-end auditable voting systems can provide the voter with a receipt that can be taken home. This receipt does not allow voters to prove to others how they voted, but it does allow them to verify that the system detected their vote 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. The city of
Takoma Park, Maryland used
Scantegrity II for its November 2009 election. 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, California 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 punched 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.
Hardware Inadequately secured hardware can be subject to
physical tampering. Some critics, such as the group "
Wij vertrouwen stemcomputers niet" ("We do not trust voting machines"), charge that, for instance, foreign hardware could be inserted into the machine, or between the user and the central mechanism of the machine itself, using a
man in the middle attack technique, and thus even sealing DRE machines may not be sufficient protection. This claim is countered by the position that review and testing procedures can detect fraudulent code or hardware, if such things are present, and that a thorough, verifiable
chain of custody would prevent the insertion of such hardware or software.
Security seals are commonly employed in an attempt to detect tampering, but testing by
Argonne National Laboratory and others demonstrates that existing seals can usually be quickly defeated by a trained person using low-tech methods.
Software Security experts, such as
Bruce Schneier, have demanded that voting machine
source code should be publicly available for inspection. Others have also suggested publishing voting machine software under a
free software license as is done in Australia.
Testing and certification One method to detect errors 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 be changed.
Cost Cost of having electronic machines receive the voter's choices, print a ballot and scan the ballots to tally results is higher than the cost of printing blank ballots, having voters mark them directly (with machine-marking only when voters want it) and scanning ballots to tally results, according to studies in Georgia, New York and Pennsylvania. ==Adoption worldwide==