Maybe my question is stupid, but, why you need to rehash each block after a changed block when changing data in a blockchain?
Each block contains a hash of its data and hash of previous block. If I change the data in block № 9000, then block № 9001 will refer to a nonexistent block. The Chain will be broken. Every article that I read says something like:
To make this work, you will need to rebuild and rehash each block following the tampered block, replacing the contents of the previous-block-hash pointers.
But, if block contains only hash of previous block, why can't I just change the previous' block hash value in block № 9001 if I change data in block № 9000? Wouldn't that restore the chain?