the Great Filter of private communication

[coderman]

we have the maths! we have the technology!

... yet actual robust, private communications remain elusive.

where the "Great Filter" thwarting our privacy codes?



is it usability; anything more than invisibly automatic a failure?

is it cost; anything more than zero too much to bear in the market?

is it correctness; anything less than a single mode always secure, broken?



perhaps all of these above, each a requisite element of robustness,
 further compounding the difficulty of realizing an ideal.