Zcash just sealed $1.7B in private funds. Ironwood is a quarantine, not a cleanup.
The upgrade admits the old Orchard pool can't stay open while still trying to preserve private money.

CryptoVibe Desk · zcash · privacy · protocols

- →Zcash activated Ironwood at block 3,428,143, opening a new private pool and stopping new value from entering Orchard.
- →The real story is supply integrity, because the old pool now has to drain without pretending the bug never existed.
- →Watch Ironwood migration over the next month, especially whether wallets move serious ZEC without breaking normal private payments.
- shielded pool → A shielded pool is a private part of Zcash where transaction amounts and addresses are hidden.
- consensus rules → Consensus rules are the checks every valid node must follow to agree on the same chain.
- nullifier → A nullifier is a hidden marker that proves a private coin was spent only once.
Zcash just turned Ironwood on. The Zebra release put NU6.3 activation at block 3,428,143 on July 28. The upgrade opens a new Ironwood shielded pool and starts closing the door on Orchard.
This is not a routine privacy upgrade. It is a live quarantine. ZIP 258 says post-NU6.3 rules stop new value from entering Orchard, while still letting value leave. That is the only number that matters in code form:
valueBalanceOrchard >= 0 enableCrossAddress = 0
At the contract level, that means Orchard can drain but not refill. New shielded activity routes into Ironwood, which has its own note commitment tree, nullifier set, and chain value pool balance. The tradeoff is privacy continuity for supply integrity separation.
CoinDesk reports Orchard held about 3.66 million ZEC at activation, worth roughly $1.7 billion. It also reported only 1,500 ZEC had moved into Ironwood at press time. Those numbers are early, but the gap is the story. If you're holding private ZEC, your bag now lives across a migration boundary.
The hard part is not making a new pool. Zcash has done pool migrations before. The hard part is admitting an old private pool can no longer be fully proven clean without turning privacy into theater. The engineers know this; the marketing team pretends they don't.
Ironwood keeps the private-money promise alive, for now. But it also makes the old Orchard risk visible by design. That is uncomfortable, and it is exactly why the upgrade matters.
Zcash was right to block new value from entering Orchard. Keeping it open after a proof-circuit bug would make supply integrity a trust claim.
Within 30 days, watch whether Ironwood passes 500,000 migrated ZEC while Orchard keeps falling with no client-level payment failures reported.
Primary links and supporting reads used by the desk for this story.
Forward this.











