The Zcash network plans to roll out the NU6.3 update, called Ironwood, on July 28. The hard fork, which is expected to become active at block 3,428,143, aims to limit ZEC assets that cannot be verified following the vulnerability detected in the Orchard sandbox. With the update, the existing Orchard pool will be closed and the amount of ZEC that can be drawn from this pool will be restricted.
Exits from the old pool will be limited
Zcash is known as a privacy-oriented cryptocurrency network and uses protected pools that can hide sender, receiver and amount information in transactions. Due to this structure, the network cannot distinguish or freeze individual coins that may be counterfeit. For the same reason, it does not seem possible for users to prove that a particular ZEC was not manufactured defectively.
Zcash founder Zooko Wilcox stated in her statement on
By design, Orchard hides transaction details. Therefore, the network cannot detect and freeze individual fake coins.
The Ironwood update will also introduce a turnstile mechanism that will regulate shots from the old pool. This system will be based on the amount of ZEC legitimately entering the Orchard pool. Any amount above this total will not be allowed to be removed from the pool. Thus, the aim is to isolate any overbuilt balances within the old pool.
Mini-dictionary: The turnstile mechanism is a technical control method that limits the total assets that can leave a legacy pool to the amount of pre-verified input. Formal verification is a security approach based on mathematical proof of certain rules.
New protected pool will be used
After the update, ZEC transactions within the existing Orchard pool will stop. The network will now operate through a new sandbox with corrected cryptographic circuits. Users in the old pool will have to use compatible wallet tools to move their assets to the new system.
The vulnerability was discovered by researcher Taylor Hornby during an audit of the Orchard repository on May 29. The bug in question could theoretically enable the production of fake ZECs, and it was also possible for this activity to not be publicly visible. The developers stopped the Orchard activity after the vulnerability was noticed. The functionality was later reopened with the NU6.2 hard fork, which included corrected cryptography.
The Zcash team states that users do not need to take any additional action before the hard fork, but wallets and exchanges may temporarily stop deposits and withdrawals during the update.
The new arrangement will create a separate area for future transactions while leaving the excess value that may have been created before the update in the old pool. Node operators will also be able to control the allowed circulating supply within this framework.
The transition schedule may change depending on the software updates of wallet providers and exchanges. Orchard balances may not be displayed on wallets that do not provide the necessary support. Some service providers have already started the transition to the new system.
