I see stories about how election is rigged or that there are security vulnerabilities and lots of people don’t believe the outcome. Why don’t they just open source everything so that anyone can look at the code and be sure the votes are tallied correctly?
How do you prove that the software installed is the same software the source code of which is available to the public?
@rockslice addressed this in another comment - you use signing certificates to verify it’s the correct code, which is a widely accepted method.
How can a voter verify this though without spending 10 minutes inside the booth?
You’re right, they can’t. That said, how can they verify some local official hasn’t taken a pay off to fudge some numbers? The public believing election results requires multiple processes each being as transparent as possible, and even then, it comes down to trust, and some people just won’t believe the results. We should design systems that are as robust and transparent as possible, and an open source machine that counts physically marked ballots is only one component.
Remote verification is possible and desirable.
Ideally news companies and hobbyists have access to do this verification before after and during the elections. Also, most local governments could and should pay an auditor company periodically to do the same audit and publish the results.
These processes exist for closed source infrastructure. They’re just better and more effective on open source solutions.