Zcash founder Zooko Wilcox has explained how the July 28 Ironwood network hard fork will address the uncertainty surrounding a key flaw in the Orchard secure pool.
Summary
- Zcash will cover the old Orchard pool, limiting how much ZEC can leave after Ironwood.
- Ironwood cannot identify individual counterfeit coins but it can stop the hidden supply that has gone beyond the Orchard escape.
- Temporary exchange and wallet disruptions may occur as providers prepare for the July 28 Zcash upgrade.
The upgrade will not identify or stop individual counterfeit coins. Instead, it will close the old pool and measure how much ZEC can leave.
In a July 19 post on X, Wilcox explained how the planned upgrade will deal with any hidden over-provisioning if the bug is exploited before developers patch it. Because Orchard hides transaction details, the network cannot prove that a fake ZEC has not been created.
Ironwood will close the endangered Orchard Lake
Ironwood, also known as NU6.3, is scheduled to start at block 3,428,143 on July 28. The development will retire the current Orchard pool and introduce a new protected pool based on a modified circuit.
According to Ironwood Zcash user reviews, users will no longer be able to send or receive ZEC within the old Orchard pool after activation. Money can only be withdrawn by conversion, which prevents ZEC from withdrawing more than was legally deposited.
The Zcash team said they believe the bug was “unexploitable,” but users will not be able to independently prove that ZEC has not been cheated. Ironwood aims to capture any excess amount within the old pool rather than allowing it to enter the wider circulation.
The Orchard bug left a provisioning query that Zcash could not prove to be exiting
Security researcher Taylor Hornby discovered the Orchard flaw on May 29 while researching a secure system. The bug would have allowed an attacker to create a fake ZEC within Orchard without leaving a public record.
As reported by crypto.news, the developers first disabled Orchard’s functionality and then restored it with the NU6.2 hardfork with fixed cryptography. No evidence of unauthorized value creation has been found, but Orchard’s privacy means that past exploits cannot be ruled out with absolute certainty.
Crypto.news later reported that Ironwood will create a new secure pool and use a turnstile to control the amount left behind. Node operators can ensure that the circulating ZEC does not exceed the amount allowed by the financial rules of the network.
Wallets and exchanges may temporarily suspend services
Zcash users do not need to act immediately before the hard fork. However, wallets, exchanges and other providers may temporarily suspend deposits, withdrawals or related services while completing software development.
The network’s official guide says Orchard users will eventually need wallet support to transfer money to the new pool. Funds may remain temporarily unavailable for wallets that have not yet added the necessary transport tools.
The July 28 activation also follows Zcash’s move away from the legacy zcashd client. Providers still completing that migration may need more time before fully supporting Ironwood.
Zcash adds additional security checks after an error
The Orchard incident led to increased security activity across the Zcash ecosystem. As reported by crypto.news, an AI-assisted review using Anthropic’s Mythos program found no additional vulnerabilities after the initial flaw was disclosed.
The developers are also pursuing independent testing and formal verification of the updated cryptographic system. The work aims to reduce the risk of counterfeiting and provide users with strong ways to ensure the rules of Zcash supply.
Ironwood is dealing with an unresolved supply issue rather than a bug that has already been fixed itself. By closing the Orchard and controlling withdrawals through a turnstile, the hard fork aims to prevent any perceived counterfeit ZEC from entering circulation.
