Described herein is a technique in which the proof that an object (e.g., a document) was processed within a certain task by an entity in a workflow is chain-linked to another proof of the next task. The chain of proofs embedded within the document serves to irrefutably prove that a certain set of tasks were completed before the next task was executed on the object. It is thus difficult, if not impossible, for a user to alter the actions on previous tasks without destroying the chain of proofs.