Zcash has successfully completed its Ironwood network upgrade, introducing a new shielded pool designed to improve security and protect the cryptocurrency’s supply from potential counterfeiting risks.
The upgrade went live at block height 3,428,143 through the NU6.3 network update. Developers say the new Ironwood shielded pool replaces the older Orchard pool and strengthens confidence in Zcash’s supply integrity after concerns were raised about a vulnerability discovered earlier this year.
Although Ironwood is now active, the Orchard pool has not been completely shut down. Users can still withdraw funds from Orchard, but it no longer accepts new shielded transactions. So far, more than 40,000 ZEC have already been moved into Ironwood, while around 3.6 million ZEC remain in Orchard waiting to be migrated.
Following the upgrade, ZEC briefly dropped about 9% to around $460 before recovering to roughly $475. The cryptocurrency has experienced significant price swings over the past year, especially after details of the Orchard vulnerability became public.
The main reason for the upgrade was a flaw known as the Orchard “infinity” bug. Researchers discovered the issue in Orchard’s zero-knowledge proof system and said it could have theoretically allowed someone to create counterfeit ZEC without immediate detection. Developers stressed that they found no evidence the flaw was ever exploited.
Even after the bug was fixed, Zcash developers decided to build a completely new shielded pool rather than continue relying on Orchard. The goal was to provide stronger guarantees that the network’s total supply remains accurate.
Ironwood introduces a separate accounting system that allows the network to independently track funds entering and leaving the new shielded pool. It also includes a mechanism called a “turnstile,” which helps prevent any potentially invalid coins from moving into the new system.
Another major feature of Ironwood is its formal mathematical verification. Researchers completed a machine-checked proof showing that, under the system’s design assumptions, Ironwood cannot create undetectable counterfeit ZEC. The verification process involved thousands of mathematical proofs and was completed by multiple teams of researchers and cryptography experts.
The new shielded pool also includes technology designed to help the network adapt to future advances in quantum computing, although additional upgrades would still be needed before Zcash becomes fully resistant to quantum threats.
The Ironwood project was developed through a joint effort involving several organisations, including Shielded Labs, the Zcash Open Development Lab, Project Tachyon, Valar Group, and the Zcash Foundation.
With the upgrade now complete, attention is turning to the migration of the remaining funds from Orchard into Ironwood as Zcash gradually phases out the older shielded pool and moves fully to its new security model.
