Zcash has activated the Ironwood network upgrade, replacing the Orchard shielded pool with a new private pool.

The upgrade is designed to prevent any potentially counterfeit coins from leaving the retired pool while preserving transaction privacy. Ironwood also introduces quantum-resistant transaction records and formally verified cryptography intended to reduce future security risks.

Weeks after a critical vulnerability triggered a market rout and raised questions about Zcash’s supply, the privacy-focused cryptocurrency has now activated Ironwood to ensure that any counterfeit coins can never enter circulation.

The Ironwood upgrade retires the Orchard shielded pool, which holds roughly 3.7 million ZEC worth about $1.7 billion, and starts migrating users into a new shielded pool. It also introduces new accounting rules for Zcash’s circulating supply while maintaining the network’s privacy guarantees.

The path to Ironwood began in May, when security researcher Taylor Hornby, using Claude Opus 4.8, discovered a four-year-old flaw in Orchard that could have allowed an attacker to create counterfeit ZEC. Developers issued an emergency patch in June, but because shielded transactions are designed to conceal their details, there was no way to determine whether the vulnerability had ever been exploited.

That uncertainty led to a sharp selloff, with Zcash falling 38% as investors questioned whether the cryptocurrency’s supply could be trusted.

To address the issue, Zcash founder Zooko Wilcox proposed Ironwood, which replaces Orchard with a new shielded pool and a “turnstile” accounting system that prevents more ZEC from leaving the old pool than was verifiably deposited. As a result, any counterfeit coins, if they exist, remain permanently trapped.

News of Ironwood helped Zcash rebound, with the cryptocurrency recovering roughly $2.5 billion in market value in early June as investors welcomed the proposed fix. The coin currently trades for roughly $464, with a market capitalization just below $8 billion.

By July, developers had completed extensive testing while exchanges, wallets, and mining pools prepared for the Ironwood upgrade. With Ironwood now live, Zcash also gains quantum-resistant transaction records and a formally verified proof circuit intended to reduce the risk of similar vulnerabilities in the future, a notable change for a network whose value proposition depends on both privacy and confidence in supply integrity.

Some critics, including privacy infrastructure provider Nym, argue that the migration creates a temporary privacy risk.

“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.

Because every Zcash holder must move funds into the new shielded pool, Nym said users who migrate without additional protections could expose information linking their IP address to their wallet balance. To reduce that risk, Zcash developers have advised users not to rush the migration and recommend using privacy tools such as Tor or NymVPN while moving funds.