How to steal an election

This isn't a cookbook recipe for how to do it, but it is good basic introduction to vulnerabilities in electronic voting systems. The article points out that a major concern is where undetectable fraud intersects with wholesale fraud (types of fraud that might affect an entire election) and goes over current electronic voting technologies and their vulnerabilities.

http://arstechnica.com/articles/culture/evoting.ars

The article concludes by noting that current standards for electronic voting systems are weak, voluntary, and not meaningfully secure. Evaluations of systems are paid for by vendors and are voluntary.

These systems must be required to have a paper trail. Even that might not be enough, but if the voting system doesn't have that, it's very hard to be assured that no fraud occurred. They should also be reviewed by an independent entity and the reviews should be available to the public.