Zcash testnet has begun rolling out consensus changes for the Ironwood upgrade, developers' response to a four-year-old bug in the Orchard shielded pool disclosed in early June that could have allowed unlimited counterfeit ZEC to be minted. The disclosure crashed ZEC from roughly $630 to $303 before an emergency patch. Built jointly by Shielded Labs, the Zcash Foundation, ZODL and Valar Group, Ironwood adds a new shielded pool and caps supply through the existing turnstile mechanism, targeting mainnet activation in late July at block 3,417,100.
This is more than a bug fix: Ironwood lets any node operator independently verify ZEC's supply is sound, something Orchard's privacy made impossible to confirm before. One risk worth watching: coins left in the legacy pool after zcashd's deprecation could get stranded, so wallets and exchanges need migration support ready ahead of activation.
Watch for the block 3,417,100 activation, completion of the independent audit on Valar's consensus implementation, and whether migration reveals any counterfeit ZEC.
