US Patent 10121019 Storing differentials of files in a distributed blockchain

Provided is a process including: receiving a request to write a new version of a document to a tamper-evident, immutable data repository; determining that the new version of the document is different from the previous version of the document; and in response to determining, storing a difference between the previous version of the document and the new version of the document in the tamper-evident, immutable data repository.