New versions instead of overwriting
A final document belongs to a document chain – all inspection reports for a specific audit, for example. A new version becomes the next revision of this chain; the old one stays next to it, unchanged. The document belongs to the tenant, not to the person who produced it – it is kept even when that person leaves the company.
Every revision records which approved template revision it comes from, in which format and profile it was produced, who produced it and when, and in which language and time zone. A fingerprint of the data used is always stored; the data itself can optionally be kept as well, encrypted.
Encrypted and stored immutably
Every final document is encrypted with its own key and placed in storage that locks it until its retention ends – following the principle “write once, never change”. The document is only returned to your application once it has been stored. So there can be no final document that your application has and Reporting does not.
Chains, journal and timestamps
Every entry in a chain contains the fingerprint of its predecessor. Anyone who changes, removes or reorders an entry breaks the chain. In addition, every tenant keeps a journal of all evidence-relevant events – from the published template to the stored document –, which is anchored with a timestamp at fixed intervals. This also exposes a history that someone with database access has consistently recalculated after the fact, provided the timestamp key is kept separate from the database.
The seal travels with the file
Before they are stored, final PDFs receive an invisible electronic seal with a timestamp – in the name of the organisation issuing the document, not of an individual. Any PDF program that displays signatures can therefore tell whether a file passed on has been changed since it was sealed. Archiving and accessibility profiles remain valid. Whether documents are sealed is decided per project.
The seal is a technical safeguard of integrity. How it is to be classified legally is for you to assess within your own requirements.
Verify whenever you are asked
For every revision you can check whether chain, encryption and content are consistent. The result shows that a document has not changed since it was stored, which template revision it was produced with, and who stored it and when. Whether the underlying data was correct remains the responsibility of the application that supplied it.