On July 28, 2026 at block height 3,428,143, Ironwood NU6.3 activated on Zcash mainnet.
The Ironwood NU6.3 network upgrade introduces a new shielded pool designed to strengthen Zcash’s security and make the integrity of its circulating supply independently verifiable. With activation, the original Orchard pool is now restricted, and funds exiting Orchard must pass through Zcash’s turnstile to enter Ironwood.
Ironwood is the culmination of a coordinated effort across the Zcash ecosystem to respond to the Orchard soundness vulnerability discovered in late May of this year and further hardens the protocol for the future. Formally verified and independently auditable, this new shielded pool represents a significant step forward for Zcash in its mission to develop and scale unstoppable private money.
No performance improvements were included in this release.
Users should update to the latest versions of their Zcash apps and software.