code: def _transform_key(self, masterkey):
          
  
          aes = AES.new(self._transf_randomseed, AES.MODE_ECB)
  
          # Encrypt the created hash
          for _ in range(self._key_transf_rounds):
              masterkey = aes.encrypt(masterkey)
  
          # Finally, hash it again...
          sha_obj = SHA256.new()
          sha_obj.update(masterkey)
          masterkey = sha_obj.digest()
          # ...and hash the result together with the randomseed
          sha_obj = SHA256.new()
          sha_obj.update(self._final_randomseed + masterkey)
          return sha_obj.digest()
docs: This method creates the key to decrypt the database