Computational information processing has gradually supplanted traditional records and recordkeeping for the physical record, undermining practices centered on the “moral defense” of the record and supplanting them with practices centred on datafication. Prioritizing data malleability rather than the defense of information from manipulation and corruption has, this chapter argues, contributed to the current diminution of the trustworthiness of information and an unravelling of society’s evidentiary foundations. Fields such as archival science and the law have long considered questions of how records may testify to the events and actions of which they form a part – serving as proofs of claims, that is, as evidentials – but research in the field of computing has only relatively recently focused on these issues. Despite its roots in computing culture, blockchain technology offers the promise of an immutable ledger that may halt the processes of datafication contributing to the current widespread potential for manipulation of records. The design and spirit of blockchains – offering the ability to cryptographically “fix” the record, chaining it in place so that any tampering is extremely difficult and immediately evident – harks back to a pre-digital past when the materiality of paper records more readily fixed in place transactional “facts” and protected their integrity from manipulation.