The disks were delivered with an unsigned note to former Democratic Delegate Cheryl Kagan, an outspoken critic of the paperless electronic voting machines. The note said the disks had been "accidentally picked up" in the state election board offices.
Michelle Crnkovich, a spokeswoman for the FBI in Baltimore, said she could not comment on the investigation except to confirm that the agency had been contacted and asked to look into how the tapes reached Kagan's office.
Ross Goldstein, deputy elections administrator, said the disks did not belong to the Maryland board, but acknowledged that the software was used in the 2004 election. The disks contained labels indicating they came from testing labs that the state paid to test the reliability and security of the touch-screen voting machines made by Diebold, Inc.
Gov. Robert Ehrlich questions the reliability of the touch-screen machines and has suggested that Marylanders use absentee ballots if they have any doubts whether their votes will be counted accurately.
"This raises yet another unanswered question with regard to Diebold technology," said Henry Fawell, a spokesman for the governor.
This is another recent instance in which the security of electronic voting machines was brought into question, just weeks after a Princeton University study published in September demonstrated how at least one version of Diebold's electronic voting machines could be easily hacked to switch votes without leaving any trace of the corrupting software. A virus could also be spread from machine to machine via the memory cards used to tabulate votes. Diebold claims that the machine software studied is no longer in use.
In other developments:
In Maryland, the computer disks mailed to Kagan contained software for both the touch-screen machines and for the state board's computer election management system, which tabulates votes from the individual machines when voting ends on election day.
Mark Radke, a spokesman for Diebold, said the software now used for the touch-screen machines in Maryland has many new security features not included on the earlier computer code. He said the labels on the disks refer to code that is no longer used in Maryland, but is used in "a limited number of jurisdictions."
Avi Rubin, a Johns Hopkins University computer scientist who was among the early critics of paperless electronic voting systems, examined the disks at the request of The Washington Post. He said Friday he could not say whether the fact that the disks were turned over to Kagan represents any additional security threat for the general election in Maryland and elsewhere.
"The code gives somebody the opportunity to define the weaknesses in the system," he said. "Maybe another copy went to somebody else."
A statement issued by Diebold said it would "take years for a knowledgeable scientist" to break the encryption used on the software disks delivered to Kagan. But Rubin said the data files were not encrypted on the disk containing the Ballot Station software that runs the voting machines.
EDITOR'S NOTE: In a previous version of this story, The Associated Press reported erroneously that Diebold Inc., a maker of voting machines, acquired LHS Associates. LHS, which is based in Methuen, Mass., is a vendor of Diebold equipment but it is not part of the company.