New Hampshire set to pilot voting machines that use software everyone can see

If a voting machine contains microchips, then voters have to trust that no malicious entity has managed to gain physical access to those chips since the last audit has taken place.

Even if you trust the auditors to correctly represent the wishes of all voters (and not, say, the wishes of just the two main parties) and trust that they are always given a sufficient budget and sufficient time to do their job properly (despite those parameters being controlled by the very people whose elections are decided by these machines) it seems almost impossible to prevent someone from adding an additional tiny chip[0] while the voting machine is in some locked storage location somewhere. (Again, the people with legitimate access to that storage location are also potentially malicious actors that you are trying to defend against).

Also, the threat model for elections doesn't just include the danger that the result can be altered, but that people might believe that the result has been altered, which can lead to political violence and other unstable dynamics (particularly if one side thinks "we have to cheat this time, because I heard the other side cheated last time"). So it doesn't matter if the "tiny chip from China" theory turns out to be completely false, as the mere plausability of the claim can be enough to cause damage.

[0] https://www.bloomberg.com/news/features/2018-10-04/the-big-h...