Secretary of State Debra Bowen conducted a top-to-bottom review in 2007 of many of the voting systems certified for use in California. The review, led by computer scientists from the University of California, was designed to restore the public's confidence in the integrity of the electoral process and to ensure that California voters cast their ballots on machines that are secure, accurate, reliable, and accessible. Following the top-to-bottom review, on August 3, 2007, Secretary Bowen strengthened the security requirements and use conditions for certain systems. The following documents detail Secretary Bowen's decisions and the independent experts' findings in the review.

Withdrawal of Approval and Reapproval Decisions Issued by Secretary of State Debra Bowen

Premier Election Solutions (formerly Diebold Election Systems)

Hart InterCivic

Sequoia Voting Systems

Election Systems and Software

UC Final Reports

Following are the final reports from the University of California scientists detailing their findings from the top-to-bottom review. The red, source code, and documentation review team reports are separated by voting system. The accessibility report contains findings on all of the voting systems that were reviewed.

UC Source Code Team Reports

UC Red Team Reports

UC Documentation Review Reports

UC Accessibility Reports

Public Hearing

Press Releases

Testing Security Plans

Additional Information

Following are a number of documents related to the review, including a "Frequently Asked Questions" document to help people understand how the review was designed.

Professional Qualifications of the Top-to-Bottom Review Teams

Documentation Review Team Members

The reviewers were responsible for analyzing voting system security, accessibility, usability, reliability, accuracy and protection of ballot secrecy based on relevant documentation. The reviewers had access to documents such as reports from Independent Testing Authorities (ITAs), reports and data from state certification testing, and documentation related to how the systems are designed to be used in an actual election. The reviewers were split into three teams of two or three members to review each voting system subject to the top-to-bottom review.

Source Code Review Team Members

Source code is the computer language that effectively controls how electronic voting systems operate. The source code reviewers were split into three teams of six or seven members to review each voting system subject to the top-to-bottom review. Here is a more detailed description of source code review.

Red Team Members

Red team members were responsible for testing the functions and performance of the voting systems and identifying security or accuracy vulnerabilities . The red team members were split into three teams to review each voting system subject to the top-to-bottom review. Here is an explanation of red team testing in general and the preliminary protocols that were used in the red team testing.

Accessibility Team Members

The accessibility reviewers examined the voting systems subject to the top-to-bottom review to determine whether they were accessible to voters with disabilities and voters with alternative language needs.

Draft Criteria

The draft criteria for the top-to-bottom review of voting systems certified for use in California were released for public comment on March 22, 2007. The final criteria for the review can be found in the Contract Between Secretary of State and University of California Regents

Public Comment


Voting System Vendors