If all that you’re interested in is the timestamp then you don’t even really need to have a signature at all - just the hash of the image is sufficient to prove when it was taken. The signature is only important if you care about trying to establish who took the picture, which in the case of this hospital explosion is not as important.
That proves it existed at a specific time in the past, not that it didn’t exist before that. What’s stopping a hash of the Mona Lisa on a block chain with today’s date?
It also doesn’t materialize ponies out of nothing. It can’t do everything, but surely you can see that there are a lot of situations where being able to say with confidence that “this picture existed in exactly this form at exactly this date” is a super useful thing?
If all that you’re interested in is the timestamp then you don’t even really need to have a signature at all - just the hash of the image is sufficient to prove when it was taken. The signature is only important if you care about trying to establish who took the picture, which in the case of this hospital explosion is not as important.
How is a hash of the image supposed to prove anything about when it was created?
You post it publicly somewhere that has a timestamp. A blockchain would be best because it can’t be tampered with.
That proves it existed at a specific time in the past, not that it didn’t exist before that. What’s stopping a hash of the Mona Lisa on a block chain with today’s date?
It also doesn’t materialize ponies out of nothing. It can’t do everything, but surely you can see that there are a lot of situations where being able to say with confidence that “this picture existed in exactly this form at exactly this date” is a super useful thing?
It doesn’t prove when it was created, only that it existed. Previous poster /u/lolcatnip is talking about creation date
And that’s all I’m saying that it does.
As I said, it’s not perfection for every possible application. But it is still highly useful in many applications.
Ah, I thought you were saying the hash proved something on its own. Lots of weird ideas about crypto in this thread.