There's a website devoted to concerns about electronic voting. BlackBoxVoting.com tracks news stories about the all-electronic voting systems that have been introduced in recent years. It's ironic that these systems, introduced in response to problems with paper ballots in the 2000 elections, may be even more susceptible to fraud and tampering. The website includes a free PDF version of a book on the subject. The introduction provides this definition of black box voting:

Black Box Voting: Any voting system in which the mechanism for recording and/or tabulating the vote are hidden from the voter, and/or the mechanism lacks a tangible record of the vote cast.

Oklahoma's voting problems have to do with who is allowed to cast a ballot, like the recent Tulsa City Council primaries in which hundreds of voters were given a primary ballot for the wrong party. Oklahoma's vote counting mechanism itself is very solid, particularly since there are physical ballots, which the voter personally marks and examines. If touchscreen voting is used it should produce some sort of marked paper, which the voter can examine and verify that it reflects his intent. This paper would be deposited in the ballot box and would be available for use in a recount.

A number of experts have called for states to require that voting machine vendors release the source code for the programs that control the machine, so that flaws, backdoors, and other vulnerabilities could be uncovered and corrected.