Re: Still a problem for non-techies
"People are always going to be surprised by the unexpected. One way to minimize this is to expect more. Generating a random or strong pseudo random salt for every encryption you do is just good practice. Worst case it is a trivial bit of extra work for nothing. We are at a bit of an impass because you obviously can't see how compromised salts can be an issue and I am unable to see how they could not be."
Not necessarily. That's what contingency planning is all about. The thing is to plan for
But back to the thing about key sizes. In the real world, the key size hits realms of diminishing returns, plus there are issues of bandwidth and storage limitations AND they don't account for all possible avenues of attack like insiders or pwning. Ultimately, security is a risk assessment. Since perfect security is impossible, even WITH a one-time-pad, it becomes an exercise in just how far one is willing to go to be secure. At some point you hit the sweet spot where beyond that you reach diminishing returns: where it's more effort than it's worth in trying to thwart your attack (such as in making the key large enough or quantum-resistant, the adversary switches to the new path of least resistance).
That's why practical secrets like Formula X (the Coca-Cola recipe) or the WD-40 oil ratios aren't kept in electronic form at all. It's kept by a very small inner circle who performs the mixing in a black box--ingredients go in, the desired product goes out. Even then one could learn some things (at least a maximum) from the ingredients that go in, but they probably don't use everything and intentionally waste some things to throw off the trail. But that's the kind of risk assessment they made with this system.
As for the multiple sources issue, that goes back to the Trent problem. If ONE source can be compromised, how can one be certain they're not ALL compromised? Particularly by using the one compromised source to reach out to all the rest like a plague?