Best of both worlds.
If it is every time, it means at the end of the day you don't really trust the machine. You could announce results early but they wouldn't be official so what's the point?
And if the count only gets verified every once in a while, what triggers the process? Something abnormal? A random check? Something else?
What tells you the count is valid or not? How do you ensure the machine is working as it should, wasn't altered in any way and so on?
To me these problems can't really be fixed: you need the paper trail. And you can't "count" (haha) on a machine you can't really audit.
Many states conduct a mandatory sample audit of machine tabulation, either by hand or using an independent machine. I would urge those concerned about election security to lobby for this requirement in states that don't have it, as it is a practical and readily achievable improvement in election integrity.
In many states which use machine tabulation, machines are tested using a reference ballot set as part of the commissioning process, immediately before being sealed for delivery to the polling place. Once again, a requirement that should exist in those states which do not have it.
The only way to make sure it's partially secure is to audit the code and even with that you could miss stuff. Code for these things must be open.
Plus a quick google search shows (facepalm) the following (there are many others like that): https://www.nbcnews.com/politics/elections/online-vulnerable...
The three largest voting manufacturing companies — Election Systems &Software, Dominion Voting Systems and Hart InterCivic — have acknowledged they all put modems in some of their tabulators and scanners. The reason? So that unofficial election results can more quickly be relayed to the public. Those modems connect to cell phone networks, which, in turn, are connected to the internet.
The largest manufacturer of voting machines, ES&S, told NBC News their systems are protected by firewalls and are not on the “public internet.” But both Skoglund and Andrew Appel, a Princeton computer science professor and expert on elections, said such firewalls can and have been breached.
And you don't count alone, there are people with you who count with you and who double check what you do.
It works the following way. You legally must have: - one person who opens the envelope containing the ballot and unfolds it - one who reads out loud the ballot - at least two who write down what the person above said
And all that is supervised by the same people who were manning the polling station (at least 4 them).
So it becomes a lot harder not to trust humans when you have at least 4 persons who saw the ballot and a couple others observing if everything is being done as expected.