Zcash locks in July 28 for Ironwood: the Orchard patch finally stops picking fruit 🍃

Zcash's Ironwood network upgrade is scheduled to activate on July 28 at approximately 8 a.m. EST, closing the existing Orchard private transaction pool that was exposed to an "infinity" bug earlier this year. Zcash core developer Sean Bowe said Thursday that "Zcash's Ironwood mainnet activation height has been set and tagged! All of the major organizations are committed to activation of NU6.3 at height 3428143, which is approximately July 28th at 8AM EST." The activation height of 3428143 confirms the upgrade will go ahead one week later than its earlier target date of July 21.

The Ironwood upgrade, announced in June after the Orchard bug was disclosed in May, shuts down the current Orchard pool, prevents new activity within it and creates a new shielded pool. Funds leaving Orchard must pass through an accounting checkpoint before entering Ironwood, a process that could yield evidence on whether any counterfeit Zcash (ZEC) tokens were produced through the vulnerability. "As users migrate funds from the existing Orchard pool to the new pool, any hypothetical counterfeiter faces a choice: attempt to move counterfeit funds and risk exposing their existence, or leave them behind and risk being unable to move them in the future," Shielded Labs said in June, when it also floated the possibility of delaying activation.

Shielded Labs had warned that exchanges, mining pools and wallets would not have enough time to prepare their systems for a late-July mainnet activation, but Bowe's latest comment signals the community is moving forward. The May disclosure of the Orchard bug drove ZEC down 50% to $299.25 from $602.68 on June 3, and the token has since partially recovered, trading at $492.61 at the time of writing.

Separately, Zcash passed a supply milestone this week, with more than 80% of its maximum 21 million ZEC now issued. A Monday post from ru