sealForge

How it works

A sealed-bid auction where the price is public, the bidders aren’t, and you don’t have to trust the organiser or us. Here’s what happens, what stays private, and what doesn’t.

An auction, step by step

  1. Three trustees hold the escrow

    Before bidding opens, three trustees generate the escrow key together, each on their own machine. Any two of them can sign refunds and the payout; one alone can’t, and the auction server holds no key at all.

  2. You bid with a shielded payment

    You scan one QR code with any Zcash wallet. The payment goes to the escrow in Zcash’s shielded pool, with a memo holding a sealed commitment and a fresh refund address. Your receipt is created in your browser and never sent to us.

  3. After close, anyone can check the result

    The organiser publishes the clearing price, every bid’s outcome, a Merkle root and the escrow’s viewing key. With that key, anyone can rescan the chain and recompute the result. If a single number differs, the audit fails. Your receipt proves your own bid was counted.

  4. Refunds come back in pieces, on purpose

    Whatever you didn’t spend comes back as several standard-sized notes, released at random times over a few hours and mixed with other bidders’ refunds, so they can’t be matched to your bid.

What stays private

  • Who bid. The published viewing key shows amounts and memos arriving at the escrow, never who sent them.
  • Bid amounts, until close. The public sees nothing while bidding is open. In auctions marked sealed reveal, nobody sees amounts at all, not even the trustees: you deposit a standard budget and reveal your bid after the close.
  • Where your refund goes. Refunds go to the fresh address in your memo, in pieces that blend in with everyone else’s.

What doesn’t

  • In ordinary auctions, the trustees and the auction server see bid amounts while bidding is open. The auction page says which kind of auction it is.
  • After close, amounts are public, so anyone can check the price. They aren’t linked to you.
  • Your own wallet’s history. If you reuse a refund address or move refunds out all at once, you can undo the mixing yourself.

Check us

Every published auction has an audit page. For a check that trusts nothing on this site, run the open-source auditor against any Zcash node you choose. The full threat model, security review and evidence are in the repository.