Should "Fifty Shades of Gray" be the New Black?
Convenience is a subjective quantity. It is much handier to just leave your keys in your ignition switch than to have to keep track of them or fish around in your pockets every time you want to do something as routine as open your car door or start the engine. (Don't we all just love car-computer analogies?)
Full disclosure has been shown to be the most reliable way to get companies to fix security problems in their software..
Bugs will be found and exploited privately whether public disclosure takes place or not. There is a thriving market for zero-day exploits--exploits that are then used either by governments of criminal organizations to render computing systems to be less reliable and/or secure than their owners would expect them to be.
Some convenience will always have to be sacrificed in the interest of security, whether the system in question is a computer, a car, or a house. The only way to absolutely maximize convenience is to absolutely sacrifice security. (and privacy)
" Even if signals in the chip were moving at the speed of light, a chip running above 5GHz wouldn't be able to transmit information from one side of the chip to the other."
At 300 Megameters per second, the signal would travel 6cm during one clock cycle. Just how large of a "chip" are we talking about, and how much clock skew can we design into our processor?
I call bullshit on the above statement.
"I have no information on the subject, but my educated guess is..."
Without information, you cannot make an 'educated' guess. What you made was a guess. And, you guessed wrong.
When dealing with 'users' of the caliber that you describe, it really isn't possible to securely exchange data. Unfortunately, most 'users' can't be trusted not to have the file scraped off of their own box once they've received it. Without a minimal amount of computer knowledge and skills (which appears to be beyond the capabilities of most users), it just isn't possible to guarantee any security at all.