Computing Applications

Statewide Databases of Registered Voters

A study of accuracy, privacy, usability, security, and reliability issues.
  1. Introduction
  2. Executive Summary

ACM’s U.S. Public Policy Committee (USACM) formed a committee last year to provide states with guidance on implementing the statewide voter-registration databases mandated by the Help America Vote Act, a federal law passed in the wake of the controversial 2000 Presidential Elections. The committee recently released a report on its study; for the complete version please visit

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Executive Summary

The voter registration process may seem simple to most voters. They give their names, addresses, birth date, and in some cases party affiliations to election officials with the expectation that they will be able to vote on Election Day. In reality, election officials must oversee a complex system managing this process. They must ensure that the voters’ information is accurately recorded and maintained, that the system is transparent while voter information is kept private and secure from unauthorized access, and that poll workers can access this information on Election Day to determine whether or not any given voter is eligible. A well-managed voter registration system is vital for ensuring public confidence in elections.

State and local governments have managed voter registration using different approaches among different jurisdictions. In 2002, Congress sought to make these disparate efforts more uniform by passing the Help America Vote Act, which required that each state have a computerized statewide voter registration database. In implementing this mandate, state and local governments still have differing approaches, but it is clear that information technology underpins each of their efforts. While technology will help election officials manage this complex system, it also creates new risks that must be addressed.

This study focuses on five areas that election officials should address when creating statewide voter registration databases (VRDs): accuracy, privacy, usability, security, and reliability. Each chapter contains detailed discussions and recommendations. The following are some of the overarching goals for VRDs and selected recommendations for achieving them.

1. The policies and practices of entire voting registration systems, including those that govern VRDs, should be transparent both internally and externally.

VRDs control access to voting; therefore, they have a direct impact on the fairness of elections, as well as the public’s perception of fairness. It must be possible to convince voters, political parties, politicians, academics, the press, and others that VRDs are correct and are operating appropriately. Internal procedures and interfaces also must be clear to election workers in order to minimize errors. Transparency can be provided by allowing voters to verify their voter registration status and data; publicly disclosing outside data sources that officials use for verification; indefinitely keeping a secure write-once VRD archive in electronic form to allow audits of previous elections; and using independent experts to audit and review VRD security policies. Other goals such as accountability, audits, and notification also support transparency and are discussed here.

2. Accountability should be apparent throughout each VRD.

It should be clear who is proposing, making, or approving changes to the data, the system, or its policies. Security policies are an important tool for ensuring accountability. For example, access control policies can be structured to restrict actions of certain groups or individual users of the system. Further, users’ actions can be logged using audit trails (discussed here). Accountability also should extend to external uses of VRD data. For example, state and local officials should require recipients of data from VRDs to sign use agreements consistent with the government’s official policies and procedures.

3. Audit trails should be employed throughout the VRD.

VRDs that can be independently verified, checked, and proven to be fair will increase voter confidence and help avoid litigation. Audit trails are important for independent verification, which, in turn, makes the system more transparent and provides a mechanism for accountability. They should include records of data changes, configuration changes, security policy changes, and database design changes. The trails may be independent records for each part of the VRD, but they should include both who made the change and who approved the change.

4. Privacy values should be a fundamental part of the VRD, not an afterthought.

Privacy policies for voter registration activities should be based on Fair Information Practices (FIPs), which are a set of principles for addressing concerns about information privacy. FIPs typically address collection limitation, data quality, purpose specification, use limitation, security safeguards, openness, individual participation, and accountability. There are many ways to implement good privacy policies. For example, we recommend that government both limit collection to only the data required for proper registration and explain why each piece of personal information is necessary. Further, privacy policies should be published and widely distributed, and the public should be given an opportunity to comment on any changes.

5. Registration systems should have strong notification policies.

Voters should be informed about their status, election information, privacy policies of the government, and security issues. As with audit trails, notification procedures can improve transparency; however, they are not always widely embraced. A recent survey found that approximately two-thirds of surveyed states do not notify voters who have been purged from election rolls. Voters should be notified by mail about their polling places, any changes that may affect their ability to vote, or any security breaches that expose private data.

6. Election officials should rigorously test the usability, security, and reliability of VRDs while they are being designed and while they are in use.

Testing is a critical tool that can reveal that "real-world" poll workers find interfaces confusing and unusable, expose security flaws in the system, or that the system is likely to fail under the stress of Election Day. All of these issues, if caught before they are problems through testing, will reduce voter fraud and the disenfranchisement of legitimate voters. We recommend many different ways to test various aspects of VRDs throughout the report. Examples include evaluation of VRD interfaces by laypersons and experts for consistency, feedback, and error handling; testing interfaces with real-world users and conditions, including extreme or sub-optimal conditions such as high processor load or network congestion; and allowing thorough, independent evaluations of the security and reliability of the VRD.

7. Election officials should develop strategies for coping with potential Election Day failures of electronic registration databases.

VRDs are complex systems. It is likely that one or more aspects of the technology will fail at some point. Different strategies can be employed to adjust for various failures. For example, Election Day verifications can be done via any of the following: paper systems, personal computers or hand-held devices with DVD-ROMs or other methods of holding static copies of the voter list, or via personal computers or hand-held devices connected by electronic communication links to central VRDs. Regardless of the method used, a fallback process should be devised to deal with a VRD failure. When appropriate, these processes should operate in tandem with provisional balloting and other measures designed to protect the voters’ right to vote.

8. Election officials should develop special procedures and protections to handle large-scale merges with and purges of the VRD.

One of HAVA’s main requirements is that VRDs be coordinated with other state databases (such as motor vehicle records). Ensuring that voter records reflect up-to-date information from other databases can improve the accuracy of VRDs, but coordination can introduce errors from the same databases, thereby undermining accuracy. Because large-scale merges and purges can render voters ineligible, the action should only be performed by a senior election official with procedures that force some sort of manual review of the changes. Further, if large-scale purges occur, they should be done well in advance of any election, and anyone purged from the database should receive notification so that any errors can be corrected.

Conclusion. State and local election officials face an ongoing and challenging task in creating and implementing statewide voter registration databases. We hope that the discussion and recommendations in this report will help inform officials and the public on how to meet these challenges.

In issuing this report, we recognize that many states have been working diligently toward meeting the federal requirement to have an operational statewide VRD. Both because many states will not meet this deadline, and because there will be ongoing maintenance and changes to any such system, state and local governments will also face the issues identified in this report well beyond the federal deadline. For this reason, we offer our continued guidance to officials who may wish to discuss any of the topics raised in this report.

Members of the ACM Committee on Guidelines for Implementation of Voter Registration Databases

Paula Hawthorn (retired database company executive), Co-chair of Study
Barbara Simons (retired, IBM Research and former ACM president), Co-chair of Study
Chris Clifton (Computer Science, Purdue)
David Wagner (Electrical Engineering and Computer Science, UC Berkeley)
Steven M. Bellovin (Computer Science, Columbia)
Rebecca N. Wright (Computer Science, Stevens Institute of Technology)
Arnon Rosenthal (Research Scientist, MITRE Corporation)
Ralph Spencer Poore (Consultant, Privacy and Security)
Lillie Coney (Associate Director, Electronic Privacy Information Center)
Robert Gellman (privacy and security consultant)
Harry Hochheiser (Computer Professionals for Social Responsibility)

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