If you're hiding the hash where no one can find it, how are people going to check it? If you tell people where you're hiding it, what's the point of hiding it?
Hiding it can make sense as long as you are sure it's eventually found by chance, and the finder will recognize its significance. At some point the building foundation will be torn up, and precisely at that point the hash will be revealed. Any modification before that requires knowledge of it and a somewhat sophisticated plan to modify or destroy it.
But really, you don't have to make those locations secret, you already get a lot of security by requiring an attacker to drive out into a desert to change that tablet, access a building foundation and tamper a Banksy painting. None of these are secure in the cryptographic sense, but even without secrecy that raises the bar for an attack substantially, and makes it more likely to be detected.
>Hiding it can make sense as long as you are sure it's eventually found by chance, and the finder will recognize its significance. At some point the building foundation will be torn up, and precisely at that point the hash will be revealed.
The hash could be revealed after the tampered message was found, and therefore after it would have been necessary. Imagine some critical decision was taken based on incorrect information, for example.
>you already get a lot of security by requiring an attacker to drive out into a desert to change that tablet
If you think remoteness is sufficient protection then there's no need for hashes or anything like that. Just do what 9gag did and etch your message onto stone and bury it wherever. They found the approximate location of that slab fairly quickly, but who's going to go digging in Spain just to smash a limestone slab with some memes on it? If someone is willing to do that once, doing it one or more times again is not a lot more effort.
The key factor here too is - will anyone care. If it’s some random alphanumeric symbols of no significance because no one cares or recognizes the connection to what anyone cares, you’re going to have more impact on humanity literally etching a bunch of random memes here and there.
At least one of them might be a Rosetta Stone for some future Society that way.
I think my point is, ‘why would anyone want to care?’.
If someone cares and it matters to them, it is not infeasible.
If no one cares, then it may be feasible, but is pointless. No one would ever bother to check, even if said etched-in-glass checksum was still around and findable.
The Bible isn’t vastly different from it’s original writings - or one of the most printed works ever- due to time alone. it’s because each generation finds it’s own reason for propagating what they want (and not propagating what they don’t), and that’s a necessary property for it to exist in a way anyone cares about at all after this amount of time.
Otherwise it would just be (at best) some rotten parchment in a language no one can read, and of at most academic interest in some caves in the Middle East. If someone came up with a checksum on such rotten parchment, the only people who would care would be math nerds - assuming anyone ever found it.
