Although electronic voting machines have become a regular feature at the ballot box, a growing number of critics have raised concerns about the machines' security, reliability and accuracy.

Proponents tout the machines' efficiency, ease of use and accessibility to voters with disabilities, but skeptics fear computer errors or fraud could disenfranchise voters or secretly change election results.

The critics found some vindication earlier this month in a Government Accountability Office report that showed some machines were insecure and unreliable, and their flaws have lost or miscounted some votes in recent federal elections.

Without identifying the specific voting systems involved, GAO reported that in some cases:

• Ballots already cast, ballot definition files and audit logs could be modified.
• Systems had locks that could be easily opened and unprotected power switches.
• Local voting officials misconfigured their machines.
• Voting systems failed while in use during elections.

GAO found some local elections officials had no idea how to deal with problems that could arise with the machines during an election.

"It is important to note that many of the reported concerns were drawn from specific system makes and models or from a specific jurisdiction's election," GAO auditors wrote in the report. "There is a lack of consensus among election officials and other experts on the pervasiveness of the concerns."

GAO made specific recommendations for the Election Assistance Commission, a body established through the Help America Vote Act of 2002. The recommendations include determining the necessary changes for making systems more secure and reliable and improving management and support to state and local elections officials.

GAO recommended that authorities collaborate with the National Institute of Standards and Technology to establish a process to continuously update the National Software Reference Library for voting system software and promote use of the library for checking software.

GAO also recommended that election officials find ways to share information on the vulnerabilities of voting systems.