Blockchain is a type of DLT in which records are organized in blocks that are appended to a single chain using cryptography and distributed consensus. Each block contains a time stamp and a link to the previous block, ensuring that data in a block cannot be altered retroactively. This makes blockchain a good choice for the recording of events, provenance tracking, and document life-cycle management. Signing a PDF in the blockchain instead of storing a signature in a PDF reduces the complexity of the code for a developer who needs digital signing and verification functionality. The same principle can be used in many other use cases to implement a document workflow, to keep track of the location of a document, and much more.