Before the Princeton hack...Diebold TS == 'Worst Ever Security Flaw':

[tiptoe]

Worst Ever Security Flaw Found In Diebold TS Voting Machine —Alan Dechert, President, The Open Voting Foundation

This may be the worst security flaw we have seen in touch screen voting machines,. says Open Voting Foundation president, Alan Dechert. Upon examining the inner workings of one of the most popular paperless touch screen voting machines used in public elections in the United States, it has been determined that with the flip of a single switch inside, the machine can behave in a completely different manner compared to the tested and certified version.

"Diebold has made the testing and certification process practically irrelevant," according to Dechert.
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The most serious issue is the ability to choose between "EPROM" and "FLASH" boot configurations. Both of these memory sources are present. All of the switches in question (JP2, JP3, JP8, SW2 and SW4) are physically present on the board. It is clear that this system can ship with live boot profiles in two locations, and switching back and forth could change literally everything regarding how the machine works and counts votes. This could be done before or after the so-called "Logic And Accuracy Tests".
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This is not a minor variation from the previously documented attack point on the newer Diebold TSx... the TS, a completely legal and certified set of files can be instantly overridden and illegal uncertified code be made dominant in the system, and then this situation can be reversed leaving the legal code dominant again in a matter of minutes.

These findings underscore the need for open testing and certification. There is no way such a security vulnerability should be allowed. These systems should be recalled.

The phrase "so-called Logic and Accuracy Tests" in the above excerpt is also used in the Princeton Demo Video (01:59), seeming to imply a limited usefulness of such tests -- in the context of designs with "ability to implement conditional logic, including date and time-sensitive triggers" -- for only the most basic of exploits.