The Zcash development team ZODL, together with Shielded Labs, Tachyon, Valar Group, and the Zcash Foundation, finalized consensus rules for the Ironwood upgrade. Set to activate at block height 3,417,100 in late July, the upgrade creates a new shielded transaction pool built from patched code, effectively locking the vulnerable Orchard pool. ZEC surged 45% from a Friday low around $300, currently trading near $461.
Orchard vulnerability triggers new pool
A week after the Orchard shielded pool's infinite mint bug went public, Zcash developers chose to build an entirely new privacy pool rather than patch the old one. Ironwood introduces a flag bit between the old and new Orchard pools, preventing new transactions from entering the old pool while only allowing change outputs. This makes the old pool a one-way exit.
Coupled with Zcash's existing turnstile mechanism — an on-chain accounting system that tracks ZEC flows for each pool — any attempt to withdraw more ZEC from the old pool than legitimately deposited is rejected outright. The developers describe the effect as causing counterfeit ZEC hidden in the old pool to either be exposed during migration or permanently trapped inside, effectively burned.
Wallet-side migration and buffer
Existing Orchard addresses remain valid. Wallets supporting Ironwood will offer a one-click migration tool. Valar Group built a wrapper to give users still on older zcashd wallets a transition period. Once the upgrade activates, anyone running a node can verify from consensus rules that ZEC's circulating supply has not been inflated — precisely what the market wanted to hear since the Orchard bug was disclosed.
The market's response was swift. ZEC had fallen 48% to near $250 after the bug emerged, touched a low around $300 last Friday, then bounced 45% within two days of the Ironwood proposal. At press time, ZEC stands at approximately $461.