Zcash may delay Ironwood upgrade due to readiness gaps

Shielded Labs warned the Zcash network may delay the Ironwood upgrade scheduled for late July because exchanges, mining pools and wallet providers may not have time to replace the legacy zcashd client with the Z3 stack.

Ironwood would close new activity in the Orchard shielded pool, open a replacement private pool and add an accounting checkpoint designed to prevent more ZEC from exiting Orchard than entered. The upgrade was proposed after researchers identified an “infinity” bug in Orchard that could, in theory, allow creation of unlimited counterfeit ZEC inside the pool.

Developers report no evidence the flaw was exploited, but Orchard’s privacy features make it impossible to prove that no fake coins were created.

At the same time, the project plans to retire zcashd and move ecosystem software to the Z3 stack. Z3 separates functions into Zebra for running network nodes, Zaino for supplying blockchain data to applications and Zallet for wallet functions. Official guidance for operators notes that some zcashd features do not have direct replacements, requiring system changes by exchanges, pools and wallets.

Jason McGee, executive director of Shielded Labs, wrote on a community forum that Zallet and Zaino remain under development and are not yet ready for production. He reported that feedback from infrastructure providers showed a split: some expect to complete changes by late July while others need more time. No decision to delay Ironwood has been finalized.

Zcash founder Zooko Wilcox wrote that security reviews have not uncovered additional serious bugs and that developers are continuing verification work on the new stack ahead of any activation.

If operators cannot complete migrations before zcashd is retired, exchanges and wallets could face interruptions or degraded service.

Orchard is Zcash’s primary shielded pool for private transfers. The Z3 stack replaces a single monolithic client with separate components for node operation, data provision and wallet management, a change that requires broad adoption across the ecosystem to work as intended.