Zcash Ironwood Upgrade Goes Live Tomorrow, Locks 3.76M ZEC in Old Pool

The Zcash Ironwood upgrade goes live tomorrow, July 28, at block 3,428,143, locking the Orchard private pool containing 3.76 million ZEC worth approximately $1.89 billion, or roughly 22% of all ZEC in circulation. Users will only be able to withdraw funds from the locked pool, not deposit new funds into it. The upgrade adds a quantum safeguard that protects funds in the new pool if quantum computers ever break current cryptographic standards. Coins remaining in the old pool cannot be rescued under such a scenario.

The change follows a counterfeiting vulnerability discovered in May that could have allowed fake ZEC creation in the Orchard pool. Because Orchard hides transaction amounts, the vulnerability could not be proven fixed without locking the old pool. Users migrating funds must be aware that moving coins out of the old pool is publicly visible on-chain; however, IP address privacy risks arise when wallets communicate with servers during migration. Zcash founder Zooko Wilcox advised users to enable Tor or Nym before moving funds to prevent IP-to-balance linking.