Blockchain records should originate from a timeless source to make the system foolproof

The timeless nature of information stored in blockchains not only makes it auditable at any given time but also contributes to building trust among users. For example, if one wants to log that The New York Times wrote an article about Donald Trump on May 29, 2017, it is not sufficient to just place a link to the article, note down the date and time, and add it as a record on the blockchain. Storing a cryptographic hash of the article on the blockchain, while archiving the whole article in a regular database, makes the information timeless. Storing re-computable hashes enables one to prove at any time, with negligible error probability, that the article is indeed what was logged on the blockchain originally.