Patents System were managed on Blockchain it could be a ledger of filings. The filing could be identifiable via a key, but otherwise encrypted with a private key. The public key, at the time of filing would not be disclosed. When the pronouncement is made (approved/rejected), the public key would be disclosed in another entry in the Blockchain. If the patent had suffered modifications, those could be additional filings in the ledger with the encryption via the same private key and referring to the same ID. With this system, patent and trademark applications couldn’t be backdated or altered without that being evident too.