The Ironwood upgrade on Zcash goes live Tuesday at block 3,428,143, locking the old Orchard private pool that holds 3.76 million ZEC — about 22% of circulating supply, worth roughly $1.89 billion. The upgrade forces all funds to migrate through a turnstile mechanism designed to prevent a bug discovered in May from being exploited to create fake ZEC.
The bug that forced the upgrade
In May, security researcher Taylor Hornby found a bug that could have allowed an attacker to create fake ZEC. The Zcash team patched it within days, but the news sent the price tumbling over 30% to $385.80. This isn't the first time a fake-coin bug has hit Zcash. A similar vulnerability in the Sprout pool in 2018 left 22,747 ZEC stuck in that pool to this day.
How the turnstile works
Ironwood introduces a turnstile at the migration point. It ensures that no more ZEC leaves the old pool than entered it, effectively blocking any fake coins from being moved. Users migrating their funds must use Tor or Nym to protect their IP address — the migration itself can link an IP to a balance, a privacy risk the developers want to mitigate.
What users and exchanges need to do
Node operators must install Zebra 6.0.0 before the upgrade to avoid disruption. Some exchanges may pause deposits or withdrawals during the migration, a sign they're behind on updates. For most holders, no action is required — old addresses will continue to work in the new pool. A dashboard by ZODL tracks funds leaving the old pool block by block. Scammers are already impersonating Ironwood migration support; users are warned to be cautious.
Quantum safeguard and price recovery
The new pool includes a quantum safeguard, ZIP 2005, designed to protect funds if quantum computers ever break current cryptography. Meanwhile, ZEC has recovered. At the time of writing, the token trades around $506, up 4% in a day, 22% in a month, and over 1,100% in the past year. The migration is expected to take some time; the ZODL dashboard will show progress block by block.
