[ketzu]

One problem of this solution is you can not verify the write in the first place, as the encrypted data is no longer publicly verifiable.

[randaouser]

you can share the encrypted data and allow anyone to perform the block hash of the file. As the data is encrypted it should be publicly accessible. EDIT

yes the data itself becomes difficult to verify. Then you must move towards are for more complicated ZKSnark or Homomorphic scheme