Zcash Activates Ironwood Upgrade After Counterfeiting Scare

Zcash has activated its Ironwood upgrade to address a four-year-old flaw in its Orchard shielded pool that could have allowed counterfeit ZEC coins to be created. The vulnerability was discovered by security researcher Taylor Hornby and sparked a sharp selloff, with Zcash falling 38% as investors questioned the cryptocurrency's supply.

The Ironwood upgrade retires the Orchard pool, which holds approximately $1.7 billion in ZEC, and begins migrating users into a new shielded pool. It also introduces a 'turnstile' accounting system that prevents more ZEC from leaving the old pool than was verifiably deposited, ensuring any counterfeit coins remain permanently trapped.

Developers had completed extensive testing by July, and exchanges, wallets, and mining pools prepared for the upgrade. With Ironwood now live, Zcash also gains quantum-resistant transaction records and a formally verified proof circuit to reduce future security risks.