How does that work exactly? Does it all still hinge on trusting a know Time Stamp Authority, or is there some way of time stamping in a trustless manner?
You can publish the hash in some durable medium, like the classified section of a newspaper.
This proves you generated it before this time.
You can also include in the hash the close of the stock market and all the sports scores from the previous day. That proves you generated it after that time.
If you are looking to prove that something happened after a certain timestamp, you can use a randomness beacon[0]. Every <interval>, the beacon outputs a long random number. Include the timestamped random number into your artifact.
You are relying upon the authority of the beacon to be random, but good practice is to utilize multiple independent beacons.
Yeah it definitely could be, though you may similarly find yourself in a spot of trusting a limited number of nodes that guarantee the chain was never tampered with.
For something like this there’s ways to minimize how much you need to trust nodes such as regularly publishing hashes to 3rd parties like HN.
Not so useful if something was edited a few minutes after posting, but it makes it more difficult for a new administration to suddenly edit a bunch of old data.
What happens as websites disappear? With a blockchain in 2090 you can point to a website post in 2060 as support that your hashes on data posted in 2030 are still valid. That’s useful when preventing people from rewriting history is the goal.
There’s also a size advantage. You can keep a diff on the archive for each hash being posted instead of the full index for every time you post a hash.
