I agree but worry about what this implies for accounting and other financial systems. If we can't trust the voting machines to tell us what the vote totals are, how can we trust the bank computers to tell us who owns what?

I would be very worried about banking security if there was only one bank and it was run by the government. Obviously, that's not the case, banks are private companies and there are thousands of them constantly competing for each other. They have a strong interest in tight security to remain trustworthy. They're also heavily regulated, probably even more than the voting system, and they're subject to financial auditing. I'm not an expert but would estimate that for these reasons banking is overall more secure than electronic voting.

I could be wrong, though. As far as I know, hardware companies nowadays cannot even be reasonably sure that the chips they use don't contain backdoors.

Now you're getting it. Trust is the overriding problem, and it is a people problem, not a tech one.

For clarification, my position is that electronic voting is not secure and cannot be made sufficiently secure to safeguard against catastrophic failure and abuse. That's orthogonal to the issue whether voters trust in the voting mechanism, which is also important.

By having enough banks, so you can switch and having a regulatory authority inspecting banks?

Particularly where the machines are all of the same type or connected to the Internet. If