The Zcash mainnet has activated the Ironwood NU6.3 upgrade, introducing a new shielded pool.

ChainCatcher reports that Zcash activated the Ironwood NU6.3 network upgrade at block height 3,428,143, launching a new shielded pool to enhance network security and make ZEC circulating supply independently verifiable.

After the upgrade, the original Orchard pool is restricted: new funds cannot enter, and existing funds must exit through a turnstile before entering Ironwood. This ensures at the protocol level that pool expenditures do not exceed verifiable income. Ironwood is based on a revised protocol that has been formally verified and independently audited, aiming to guard against risks similar to previous declarative vulnerabilities in Orchard. Wallets supporting Ironwood (such as Zodl 3.8.0) have already provided migration paths, allowing users to transfer Orchard funds to the new pool without changing their address.