Also called: blockchain anchoring, timestamp anchoring
In plain words
Anchoring writes a small commitment, usually one hash, into a public blockchain. The blockchain isn't storing your data. It's acting as a clock and a notary nobody controls: once the hash is in a block, anyone can see that it existed no later than that block's time, and nobody, including the party who wrote it, can change or backdate it.
Done right, the chain is the proof underneath, not the product. There's no token to buy or hold.
How QED Proof uses it
Every ten minutes QED Proof publishes its log's root through the Ethereum Attestation Service on Base. Today that's Base Sepolia, Base's test network; moving to Base mainnet is the next step and waits on an explicit go. The anchoring wallet's key lives in a cloud KMS, and the attester addresses are published in poaw-keys.json.
A receipt's proof.anchor names the chain (as a CAIP-2 ID), the attestation UID and the transaction. The attestation's block timestamp becomes the receipt's proven-by time. A receipt that's signed, included and anchored reaches trust level 2: it can't be backdated or silently deleted.
Example
anchor ✓ block 47,309,207
trust level 2 proven by 21:38:22
The checker confirms this against any public Base RPC, with nothing of QED Proof's in the path.