I do not put any document on the chain just a hash. I do only need proof that a certain version of the document existed at a certain time to proof that it wasn'

I do not put any document on the chain just a hash. I do only need proof that a certain version of the document existed at a certain time to proof that it wasn't altered after. Multiple revisions are ofc also possible. If you upload the same multiple times the first timestamp is enough, everything after can be ignored.