Zcash Locks the Orchard Pool, Zaps the Counterfeits, and Tells Users to Breathe 🔐

Zcash activated the Ironwood network upgrade at block 3,428,143 on Tuesday, retiring the Orchard shielded pool that holds roughly 3.76 million ZEC, about $1.89 billion, or roughly 22% of all ZEC in circulation. The upgrade introduces a new shielded pool and a "turnstile" accounting system that prevents more ZEC from leaving Orchard than was verifiably deposited, ensuring that any counterfeit coins, if they exist, remain permanently trapped. Ironwood also adds quantum-resistant transaction records drawn from ZIP 2005 and a formally verified proof circuit intended to reduce the risk of similar vulnerabilities in the future.

The road to Ironwood began in May, when security researcher Taylor Hornby of Shielded Labs identified a four-year-old flaw in Orchard that could have allowed an attacker to create counterfeit ZEC. The Zcash Open Development Lab (ZODL) issued an emergency patch within days, but because shielded transactions intentionally hide their details, there was no way to prove whether the vulnerability had ever been exploited. The uncertainty sparked a sharp selloff, with ZEC dropping as much as 38% to a low of $385.80 as investors questioned whether the cryptocurrency's supply could be trusted. News of Ironwood later fueled a rebound, with Zcash recouping roughly $2.5 billion in market value in early June; $ZEC now trades near $464, just below an $8 billion market capitalization.

For everyday users, balances inside the old pool remain safe and accessible, but funds can only be moved out of Orchard, not between addresses within it. Wallets are still finalizing the tool that handles outbound transfers, so some balances may appear temporarily stuck until the relevant software is ready. Node operators face a hard deadline: they must install the Zcash Foundation's Zebra 6.0.0 release to set the switch-over point, and some exchanges may pause deposits or withdrawals during the transition. Developers said any such pause indicates the exchange is behind, not that Zcash is broken.

The migration also carries a network-level privacy risk, according to privacy infrastructure provider Nym. "Under normal use, your shielded ZEC transactions don't reveal amounts to your wallet server, so your network exposure is limited. Ironwood changes that," Nym said in a blog post on Monday, noting that users who migrate without additional protections could expose information linking their IP address to their wallet balance. Zcash founder Zooko Wilcox reinforced the warning in the project's user guidance, writing, "So for every user, the number one most important issue is having network-level privacy (i.e. Tor or Nym) before migrating." His advice is to enable Tor or Nym first, then wait until the wallet provider confirms it is safe to move funds, and to disregard anyone claiming to offer Ironwood migration support, as impersonation scams have already appeared.

Ironwood has been live since 28 July, giving exchanges, wallets, and mining pools weeks to complete testing and prepare for the transition. With the upgrade now active, Zcash's developers say the network's supply integrity is restored and that any counterfeit ZEC tied to the original Orchard flaw cannot reach the new pool.