You would embed the hash in another cryptocurrency, like in Bitcoin. Here's a simple walkthrough of how to do it in the Bitcoin Cash blockchain for instance:

You would embed the hash in another cryptocurrency, like in Bitcoin. Here's a simple walkthrough of how to do it in the Bitcoin Cash blockchain for instance: https://whycryptocurrencies.com/timestamping_service.html https://whycryptocurrencies.com/timestamping_service.html