Transaction that cannot be stored in blocks on a blockchain

There are two methods of storing data via blockchain with On-chain and Off-chain . As the name suggests, all the data is stored inside each block on the chain in an on-chain way. Thus, if an attack happens, data can be restored and used.

You do not store any documents or hashes on-chain . Instead, a distributed cloud system stores the documents. The platform only uses a blockchain to manage and referee document access and sharing.23 Ara 2018

You store your encrypted document somewhere and then upload a hash (digital fingerprint) of that document to a blockchain . Then later you can prove that your stored document is actually the one whose hash is preserved on the blockchain.

As a best practice, it is not recommended to store the document (PDF format or otherwise) or file in the Blockchain . Different blockchain frameworks limit the size of the block which can be added to the blockchain.4 Tem 2018