Orchard

Orchard is the shielded pool protocol Zcash introduced with the NU5 network upgrade in May 2022. It uses the Halo 2 proving system, which removed the need for a trusted setup ceremony — a cryptographic requirement earlier shielded pools depended on.

In 2026, a critical flaw was found in Orchard's proof circuit. The NU6.3 upgrade ("Ironwood") introduced a new shielded pool — Ironwood — built on a corrected version of Orchard's own protocol design, rather than patching Orchard in place. NU6.3 (Ironwood) has been active on Zcash mainnet since block 3,428,143 on July 28, 2026. New shielded activity uses the Ironwood pool; Orchard remains spendable but exit-only. A turnstile limits withdrawals from Orchard to what was genuinely deposited there. Its governing ZIPs (258, 318 and 326) are still listed as Draft in the official zcash/zips index. That is a document status, not a sign the upgrade is inactive.