In the below screenshot of a litecoin explorer, you can see the OP_RETURN code is fe60c0df9ee1844bc5f4fd17c278a7ccfbc91b33cd7292a2c7d4153640203a44, which shows that our WikiTrademarks image was proven to exist on the blockchain at 22/03/2021, 17:29:39 (UTC+8:00)
What is a cryptographically secure hash?
Why a SHA256 Hash
A cryptographically secure has is created from the contents of your file.
It is virtually impossible for 2 files to share the same hash, which means that you can prove your original document exists by running it through a SHA256 hashing tool and matching it with the hash stored on the blockchain.