at about 6:37 in the video i think Ivan explains that you can’t change block data unless you have 51% or more of the hashrate and even after you are able to make the changes ounce you have said hashrate. You would then have to outpace other miners to catch up and be able to add the modified block to the chain.
Do i have that understanding correct? Could someone help break that down for me if i don’t have that correct. Thank you.