Velic

Verify it yourself

Independently re-check a Velic preservation proof on the public Filecoin chain.

This is the difference between “trust our logs” and “check the chain.” Every preservation proof Velic shows is recorded on the public Filecoin blockchain, so anyone holding a master's identifiers, even someone who does not trust Velic at all, can re-verify it independently.

The trust model

Velic does not ask you to believe its dashboard. The dashboard and certificate are a convenient view of records that live on-chain. The source of truth is the Filecoin chain, and you can go straight to it.

What you need

All of these come from the master's Verify on-chain panel on the dashboard and from the preservation certificate PDF:

ValueWhat it is
PieceCIDThe content address of the stored piece: a Merkle commitment to its bytes.
Dataset IDThe dataset's on-chain identifier on the PDPVerifier contract.
Proof epochThe Filecoin block height a proof was recorded at.
Proof hashThe hash recorded for that proof.
PDPVerifier addressThe contract that records possession proofs.
FWSS addressThe Filecoin Warm Storage Service contract managing the dataset.
Chain + explorerThe network (Calibration in this version) and the explorer to use.

The certificate PDF embeds the contract addresses, the chain ID, and the explorer links directly, so it is self-describing.

How the proof works

On a fixed cadence, the storage providers holding the master must answer a cryptographic challenge they can only satisfy if they still hold the data. Each answer is submitted to the PDPVerifier contract and recorded on-chain. Because the data is addressed by a Merkle commitment (its PieceCID), a passing proof means the bytes are present and bit-identical.

Re-verify on-chain

Open the dataset on a Calibration explorer

This version stores and proves on the Filecoin Calibration network (chain ID 314159). Open the PDPVerifier contract, using its address from the certificate, on a public explorer:

  • Beryx: https://beryx.io/fil/calibration
  • Filfox: https://calibration.filfox.info

(On Filecoin mainnet the same contracts are visible at https://beryx.io/fil/mainnet and https://filfox.info.)

Confirm the dataset is live and proofs are landing

Find your dataset by its ID on the PDPVerifier contract and confirm it is active and that proof submissions are recorded against it on the chain. This shows the master is being proven on the cadence Velic claims: roughly every 30 minutes on Calibration, daily on mainnet.

Match the proofs to your certificate

Compare the on-chain proof records against the epoch and proof hash values listed in your dashboard and certificate. If they match, the proofs you were shown are exactly the ones recorded on the public chain, not numbers Velic made up.

(Advanced) Recompute the PieceCID

For the strongest check, recompute the PieceCID from the stored piece's bytes using the same commitment scheme Filecoin uses (fr32-sha2-256-trunc254-padded-binary-tree) with any conforming PieceCID / CommP tool, and confirm it equals the PieceCID the on-chain proofs are taken against. That ties the exact bytes back to the commitment the chain attests to.

What a passing check proves

Possession + integrity, without revealing your master

A passing verification proves the storage providers possess the piece and that its bytes are bit-identical to what was stored, because the PieceCID is a commitment to those bytes. The proofs operate on ciphertext, so none of this exposes your plaintext or your encryption key. Combined with the key held for your master, an intact ciphertext means an intact master.

It does not require trusting Velic, the dashboard, or the certificate, only the public chain and the math. That is the whole point.

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