What if an attacker creates altered data and publishes it the same way by hashing it 50 times. Now you have two documents claiming to be the original and they e

What if an attacker creates altered data and publishes it the same way by hashing it 50 times. Now you have two documents claiming to be the original and they each have 50 hashes guaranteeing the integrity of the data. What if the attacker did that with 1,000 fake documents. I think your best bet is just to publish it and also launch a copy into space with a 500 year orbit. If someone in the future tries to launch a similar data-comet with a shorter orbit, it will be visible in the trajectory. There's always the danger of them sending out a robotic space probe to mess with your data "in flight".