Let a hardware ‘expert’ chime in.
If there is a way to INPUT to the machine different instructions than those that have been tested and verified and vetted, then the security is definitely compromised.
Blockchain seems to work for software data integrity; but I do not know if there is an equivalent method to be attained by hardware.
The old mechanical machines merely counted.
NOTHING was computed.
Well there are 4-6 different machines involved depending on what is installed. As far as I can tell the only computation of votes is the tally done in the County server which adds together all the votes on the precinct and absentee scanners in order to produce reports for the State board. All of those scanners have audit paper trails of what they counted. Ballot markers print out paper ballots for the voter. All of the hand recounts done in Michigan and Georgia confirmed that the Dominion voting scanners produced correct counts. If there was fraud it was done by ballot stuffing.