Proof that holds up without trusting the one who made it.
One per decision
What was asked, what was decided, why, and what happened after.
Chained
Removing or changing one receipt breaks the chain, so a gap shows.
Stamped by an outside clock
A trusted timestamp, including EU-qualified ones, shows the receipt existed at that time.
Checked offline
A standalone checker reads the receipt alone: no Vaara, no network, no key.