We don’t need a blockchain for that.
Having multiple servers which store file checksums would have much less overhead, would be easily repeatable and appendable, with no need for unnecessary computational labor. Linux mint currently uses the checksum process for verifying that an ISO downloaded is not altered in any way, and it can work for any file (preferably not humongous files).
Strive for K.I.S.S. whenever possible.
Or probably your slave labor in the private prison system.