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. Rather than patch the pool in place, the NU6.3 ("Ironwood") upgrade launched a new shielded pool — Ironwood — built on a corrected version of Orchard's own protocol design and proving system. Orchard now accepts withdrawals only; new shielded activity moves into Ironwood instead.