30 July 2003—Could a voter using an electronic voting
machine prematurely shut down the machine before the
scheduled end of an election? Could he or she vote an
unlimited number of times? Could a poll worker cause
votes to be miscounted, or modify the ballot itself?
Could all this happen with an e-voting machine that’s
being widely deployed throughout the United States?
The manufacturer, Diebold Inc. (North Canton, Ohio)
says no, but a team of four respected computer security
researchers, headed by Aviel Rubin of Johns Hopkins
University (Baltimore, Md.), says these and a variety of
other attack scenarios are all too possible. On 23 July,
Rubin and two colleagues, Tadayoshi Kohno and Adam
Stubblefield, and a fourth professor, Dan Wallach of
Rice University (Houston, Tex.), issued a 24-page
report, "Analysis of an Electronic Voting System," [http://avirubin.com/vote.pdf]
The report, which looks at source code independently
obtained from a Diebold Internet site last January,
concludes that an open process of software
development—rather than the closed, proprietary process
Diebold followed—would have resulted in a more secure
voting system. The authors of the report obtained the
code from a collection of thousands of documents
identified in a "simple Google search," according to
Beverly Harris, a journalist who is working on a book
about electronic voting (see
http://www.blackboxvoting.com for
information about the book).
Diebold, for its part, repudiates the relevance of the
analysis to actual voting conditions, but not its
bearing on the code itself. In a statement released on
25 July, the company noted that many of the insecurities
found by the researchers, "only apply if the voting
terminals are connected to the Internet or some other
public network. This is never the case."
Diebold also points out that its system complies with
the U.S. Federal Election Commission standards which all
election processes must follow, and that it has also
received federal certification from independent testing authorities.
Documents in the Diebold Internet site collection
suggest, however, that a version of the software was
used in some elections without having been passed
through the certification processes, says Douglas Jones,
an associate professor in the University of Iowa’s (Iowa
City) computer science department and a member of Iowa’s
board of examiners for voting machines and electronic
voting systems.
According to Jones, it’s also clear from the Diebold
source code that errors found when Iowa first studied
the company’s electronic voting system five years ago
have not been corrected in the intervening time.
Jones has called for the decertification of Diebold’s
system, and any other in which voting totals are
"computed entirely from electronically transmitted
totals"—that is, without a paper trail of printed
ballots. The Rubin research team came to a similar
conclusion. Describing what it calls the Mercuri method
[see "A Better Ballot Box?" by Rebecca Mercuri, IEEE
Spectrum, October 2002, pp. 46–50], Rubin’s team calls
for systems where "the tally of the paper ballots takes
precedence over any electronic tallies." A bill
introduced in the U.S. House of Representatives in May
by Rush Holt (D-NJ), the "Voter Confidence and Increased
Accessibility Act of 2003" (HR 2239), would mandate just that.