Zcash’s Ironwood Upgrade Set for July 28 to Address Orchard “Infinity” Bug

Zcash’s Ironwood network upgrade is scheduled to go live on July 28, aiming to resolve an “infinity” bug discovered in May in the privacy-focused blockchain’s main private transaction pool, Orchard. According to Cointelegraph, the upgrade will close the current Orchard pool, prevent new activity within it, and establish a new private pool for shielded transactions. Under the plan announced in June, funds leaving Orchard will need to pass through an accounting checkpoint before entering the new Ironwood pool, a mechanism that could produce evidence indicating whether any counterfeit Zcash (ZEC) tokens were created through the Orchard vulnerability.

Zcash core developer Sean Bowe said on Thursday that the mainnet activation height has been set for NU6.3 at height 3428143, which is approximately July 28th at 8AM EST, adding that major organizations are committed to the activation. Shielded Labs had previously floated delaying the Ironwood upgrade, warning that ecosystem participants such as exchanges, mining pools, and wallets might not have enough time to prepare for a late-July mainnet activation. Bowe’s comment indicates the upgrade will proceed one week later than an earlier target date of July 21. In June, Shielded Labs said Ironwood may provide evidence about whether the Orchard vulnerability was ever exploited, noting that as users migrate funds from the existing Orchard pool to the new pool, any hypothetical counterfeiter would face a choice between attempting to move counterfeit funds and risking exposure, or leaving them behind and potentially being unable to move them in the future.

Market reaction to the bug disclosure was sharp. ZEC fell 50% to $299.25 from $602.68 after the Orchard bug was disclosed on June 3, before making a partial recovery in the weeks that followed. At the time of writing, ZEC was trading at $492.61. Separately, Zcash reached a monetary milestone this week, with more than 80% of its maximum 21 million ZEC supply now issued. A post from ruZCASH on Monday reported that supply stands at 16,806,723 ZEC.