Files that stop working when their surroundings change
Perimeter security assumes you can keep an attacker out. The alternative is to make the artifact itself conditional: it stays readable only while the environment it was meant for still matches, and stops when that changes. It moves the question from who is asking to where the asking is happening.
The open question. Which environmental signals are trustworthy enough to justify destroying something?
What would kill it
False positives, recovery, and signal trust are the same problem wearing three hats. Something that destroys itself on a bad reading is worse than something that leaks.