Ironwood: Verifying the Soundness of Zcash's Circulating Supply

Shielded Labs' proposed path forward after the Orchard bug, published as an X article and developed jointly with the Zcash Foundation and the Zcash Open Development Lab. It introduces Ironwood, a network upgrade that migrates ZEC out of the compromised Orchard pool into a new shielded pool. The migration runs through a "turnstile" — an accounting boundary that exposes the aggregate amount crossing into the new pool — so that any user running the software can sum balances across pools and check that the total circulating supply has not been secretly inflated, rather than trusting a team's assurance. The post frames this as restoring an independently verifiable supply bound while preserving Zcash's shielded privacy.

It is the primary source for the remediation's design: how Zcash proposes to re-establish supply soundness without abandoning privacy.