Zcash to Activate NU6.3 “Ironwood” Network Upgrade on July 28
Key Takeaways
- •The Ironwood upgrade is scheduled to activate on the Zcash mainnet at block 3,428,143 on July 28, 2026.
- •Ironwood will introduce a new shielded transaction pool and a v6 transaction format to the Zcash network.
- •The new pool will reuse Orchard’s Action structure and the Halo2 proof system while keeping separate commitment, nullifier, value, and history components.
- •A turnstile mechanism is intended to improve oversight of ZEC supply as funds move into the new pool.
- •Zcash’s privacy model has made supply-audit mechanisms important because shielded transactions do not reveal full transaction details on-chain.
Privacy-focused cryptocurrency project Zcash is preparing to activate its NU6.3 network upgrade, codenamed Ironwood, on July 28, 2026.
According to the Zebra 6.0.0 release notes, the upgrade is scheduled to go live on the Zcash mainnet at block 3,428,143. The block height is expected to be reached at around 4 p.m. Turkish time on July 28, though block-based activations can vary with network block production.
Ironwood will introduce a new shielded transaction pool and a v6 transaction format to the Zcash network. The new pool will reuse the Action structure from the Orchard system and the Halo2 proof system, while maintaining its own note commitment tree, nullifier set, chain value pool, and transaction history metadata.
The update’s notable features include confidential notes designed to remain recoverable against potential future risks related to quantum computing, as well as a “turnstile” mechanism intended to strengthen verification of the ZEC supply.
The turnstile mechanism is designed to increase oversight of total supply after concerns over a possible security vulnerability in the older Orchard pool that could have allowed counterfeit ZEC to be created. With Ironwood, the objective is to provide stronger control over supply consistency as funds move into the new pool.
Zcash has previously faced significant criticism over the possibility of counterfeit tokens because of concerns about the ability to verify its supply. Zcash, launched as a privacy-focused blockchain, uses shielded transaction technology intended to allow users to transact without publicly exposing all transaction details. That privacy model makes supply-audit mechanisms especially important, because the network is designed not to reveal the full details of shielded transactions on-chain.
Ironwood activation on the test network was previously set for block height 4,134,000.
