Ethereum Layer2 project Taiko has released a summary of a security incident that occurred on June 21, where an attacker stole approximately $1.75 million. Despite the breach, no users incurred losses, and over $11 million in funds were safeguarded. The attack exploited a leaked signature key and verification omission, but Taiko's defense mechanisms, including a daily limit on the bridge, mitigated further damage. The vulnerability has since been patched, and the network was relaunched on July 2. Taiko's contracts and zero-knowledge proof cryptography remained intact, as the attack originated off-chain. The security committee swiftly suspended the bridge and vault to prevent additional fund transfers. OpenZeppelin's review post-recovery found no critical issues. An upgrade, Unzen, will be implemented on August 6, requiring zero-knowledge proof for every block, enhancing the network's security by preventing any single proving system from finalizing the blockchain alone.