Zcash has activated the “Ironwood” upgrade on its mainnet and halted new inflows of funds into the existing private pool, Orchard.

On July 29, local time, blockchain outlet CoinPost reported that Zcash Open Development Lab (ZODL) said the upgrade was activated at block height 3,428,143.

The move has effectively shifted Orchard into a withdrawals-focused state. Funds remaining in the existing Orchard pool can move to the new Ironwood pool only through a “turnstile” structure set up in a boundary zone. The protocol also set a cap to prevent more funds from leaving the Orchard pool than the amount it actually received.

The upgrade focuses on addressing an Orchard vulnerability. Shielded Labs researcher Taylor Hornby discovered the vulnerability in late May and reported the issue under a disclosure process. Zcash said the issue was fixed through an emergency network upgrade, and it has not confirmed evidence that the vulnerability was exploited or that there were changes in funds.

Users must move funds held in Orchard to Ironwood from their own wallets. The latest version of the ZODL-operated wallet “Zodl,” Zodl 3.8.0, supports Ironwood by default and said there is no need to create a new wallet or new address. ZODL said existing Orchard funds can be moved manually within the app, and it plans to provide an automatic transfer function that takes privacy into account soon.

A coordinated response across the ecosystem also took place. The upgrade was jointly 추진 by multiple independent teams including Shielded Labs, Project Tachyon, Valour Group, the Zcash Foundation and ZODL. Wallet providers, exchanges and node operators were also reported to have adjusted their systems in line with the schedule.

A network software transition also coincided with the timing. Support for the existing full-node software, Zcashd, ended on July 18, and consolidation into the new software, Zebra, was a long-term plan pursued even before the Orchard vulnerability came to light. As a result, the upgrade is described as a case in which vulnerability 대응 and a restructuring of the node system took place at the same time.

Key points to watch are the pace of users’ fund migration and the scope of follow-up support by wallets and exchanges. Zcash is blocking new funds from entering Orchard while phasing in procedures to move remaining funds into the Ironwood system. If the automatic transfer function is introduced, the burden of switching for existing users is expected to ease somewhat.