LOT 001

zkSNARKs #9631

Seller JACKSOxx · sealed window 2026-09-28 17:54 → 18:37 UTC

Reserve (public)

0.003 ZEC

Bids received

Slots

2 filled

Clearing price

0.009 ZEC

Paid by the winners

0.018 ZEC

Refunded to bidders

0.007 ZEC

Receipt list

what the seller published at reveal

Bids received

When (UTC)	Transaction	Amount	Who	Result
09-28 17:54	56bb6e…715a40	0.012	USER@Noir	win · pays 0.009
09-28 18:34	91fefe…575909	0.009	ROBOT-B	win · pays 0.009
09-28 18:34	4f7926…8fa22f	0.004	ROBOT-A	lose · refunded 0.004

Refund legs (shielded, from the lot wallet)

When (UTC)	Transaction	Amount	To	What
09-28 18:35	90d35a…968cbe	0.003	USER@Noir	overpayment — won at 0.012, uniform price 0.009
09-28 18:40	f29dbd…8d7b7d	0.004	ROBOT-A	losing bid refunded in full

A link on every row goes to the same transaction any explorer shows: the txids are the receipts, and each one resolves on Zcash mainnet. A third party could not have written this list from the chain alone — an explorer shows shielded transfers and nothing else, no amount, no sender, not even a bid count. So each bidder checks that their own leg appears here; that is what stops a seller from quietly dropping or inventing a bid. Amounts are published only at reveal, after the round closed.

How a bid works

closed round — kept as the record

DEMO-01 is closed and settled. No round is open right now, so nothing can be bid at the address at the bottom of this card. When the next lot opens, its UA and deadline are published here first.

Open a wallet with a shielded balance
Zodl, Ywallet, Edge, Zkool, Zingo! or Noir. A shielded send is the only requirement — no memo needed.
Send to the seller's published UA — the amount is your bid
The amount is encrypted by the shielded pool: the public and every other bidder see only that some transfer happened. Set it to the maximum price you are willing to pay — you pay that only if you win, and if the clearing price is lower the difference comes back to the address you sent from.
A memo is optional decoration only
If your wallet has a memo field you may type something readable for yourself — the protocol never parses it, the amount carries the bid:

BID 1.55 optional, never parsed

The UA that received the DEMO-01 bids (orchard, shielded):

u1s8xflwcl60d0ck2z028duyrfh5zr0tufjq07skymr9u64j6fd2s2dg2l854puzlq0vwy4xutwp2exph6hvtxw9ukaqpwfswdvgq26ksf

This is the seller's real unified (shielded) address, kept here because it is the record of the round. A shielded send is a valid bid only inside an open window — a transfer sent now would not be part of any round and is not refunded automatically.

Sealed round, in one glance

While the window was open, the amounts were encrypted end-to-end. Nobody on chain could read them — an explorer saw shielded transfers and nothing else. Only the seller's own wallet could decrypt a bid.

Bids received3

Amounts on an explorernever visible

Bidder identitiesnever visible

Bid count before closenever visible

Live high bidnot possible

Published at revealclearing price + ranking

settled at height 3,499,452
2026-09-28 18:37:46 UTC
escrow in the lot wallet at close 0.0218 ZEC
(3 bids 0.025 ZEC less the 0.003 refund
paid out at 18:35, before the close)
lot wallet balance now 0 ZEC (swept back)

Re-check it yourself

Round reportthe whole round, written up
Settlement JSONclearing price, ranking, every txid
Money trailall 12 legs, in and out
Refund receiptswhat was already returned on chain
Walkthrough video2:42 — the round, the console, the rules
Evidence deckseven pages, every figure clickable

What this does not do

stated, not hidden

The seller is a trusted party. It holds the lot keys, so it can decrypt a bid from the first block, and it can lie about the arithmetic behind the published clearing price. A third party cannot recompute that price from chain data alone — that is the price of privacy. What the chain does prove is the money: every revealed leg must be backed by a real txid paying the lot address.

No live “current high bid” exists. The amounts are encrypted, so nobody — not even the seller — can honestly publish a standing price during the round. We do not fake one.

A sent shielded transfer is final. A bid cannot be retracted after the deadline, so bid a price you are happy to pay. Custody is the seller's until the refund batch is broadcast — its txids are published above.

The asset is out of scope. Zcash has no live mainnet asset/NFT standard, so the lot's item is referenced off-chain by id/URI, and no item changed hands in DEMO-01. ShieldBid settles the price discovery, not the asset.

Full threat model, table form: docs/SPEC.md §7 — every threat, marked covered or not covered.

Before you send

✓Zodl, Ywallet, Edge — desktop & mobile, shielded send built in
✓Zkool, Zingo!, Nighthawk, Noir — community wallets, shielded send built in
✓Any wallet that can pay a u1 (unified) address — that is the only requirement
✗Exchange withdrawals — exchanges hold ZEC transparently, so the payout lands on a t1 and the amount is public
✗Multi-coin & hardware wallets — if the app has no shielded (u1) send of its own, a bid is impossible from it
✗Transparent (t-addr) sends — the amount is public on chain

Self-test: open your wallet's send screen. If it offers no shielded/private send (no u1 recipient), it cannot bid — shield your ZEC into a shielded-capable wallet first.

Bids sent before the window opens, after the deadline, or below the reserve are not counted. A late transfer is not refunded automatically — the seller returns it in the final batch.

ShieldBid · protocol SHIELDBID/1 (v0.2) · MIT Protocol spec Bidder guide Evidence deck Repository