Can you be more specific? I know that population or geographic size alone has no effect on counting complexity - the number of people counting is proportional to the number of votes to be counted. Communicating the vote totals from electoral districts can be done through the same medium as the voting machines would use, and producing final sums takes only O(log n) parallel steps.

So where does the terror, confusion, and rampant fraud come from, and what is it about Brazil that causes them, when so many other countries manage to avoid them?

> the number of people counting is proportional to the number of votes to be counted

Each new person is a new liability. Complexity and likelihood of mistakes do grow with number of votes.

People tick ambiguous boxes for executive functions (somehwere between 2 candidates). How do you count that?

People write numbers or names of legislative candidates. Sometimes it's illegible. Sometimes more than one candidate share the same first name or surname and the voter only wrote one. How do you count that?

The people counting the votes are members of the civil society. They're working for free in horrible conditions (hot and humid, hard chairs, pressure to finish and go back home). They're tired. They're hungry. They're thirsty. They've been many hours speaking only with a bunch of other people whom they've only met in the day and some of them are fervorously against their ideology. They make mistakes. A lot of times they miscount on purpose.

In certain regions, the "colonel" (like a local caudillo, usually a big farmer with a lot of properties and the entire town dependent on him) will not let people leave the counting place until his candidate has an acceptable count.

People leave boxes blank. The person counting ticks their favourite candidate and scores a new vote.

Fiscals from parties question decisions about all the above. Sometimes there's need to recount. The problems above compound.

Criteria for counting ambiguous votes may change during the course of the counting. Do you recount everything? Do you just pretend it's ok to change criteria depending on what results you have this far?

It also makes everything messier and take much longer. There's a reason we move away from paper-based ledgers. Those reasons also apply here but at much larger scale.

This is just a glimpse of the problems. They're much larger and deeper than I could convey in a forum post.

Of all the problems you listed, only the "colonel" is ~unique to Brazil. Every single one of the others is something a country of any size has also faced, and solved, without introducing black boxes into the system.

Well, since I took the time to answer your previous question with many examples of issues and you seem to think they have been solved, why don't you go through my list and explain how you would solve each of them, or how you have seen them solved?

That would be helpful, and would be the polite thing to do. Simply saying they have isn't.

Also please note the last paragraph on my post. It's an important one.

Also remember, the black box is heavily audited and signed off by all interested parties. There's plenty of space for improvement, but it's not only good enough but it's also much better than what I observe everywhere else and our own past.