Privacy-focused blockchain Zano took the extraordinary step Sunday of restarting its chain from block 3,833,000, removing approximately one month of subsequent transaction history after discovering unauthorized issuance involving ZANO and fUSD.
The vulnerability involved Zano’s Gateway Address system, an account-style address architecture intended to support exchanges, bridges, decentralized exchanges and payment services. TokenPost
Zano says wallet spend keys were not compromised and ordinary transaction privacy remained intact. The network’s core consensus mechanism was also not identified as the source of the vulnerability.
The problem instead allowed unauthorized ZANO and fUSD to enter circulation through the Gateway Address infrastructure. Reddit
Developers responded by restarting the blockchain immediately before Hard Fork 6, which activated at block 3,833,000 on August 26.
The consequence is severe: transactions confirmed during roughly the following month are not part of the recovered chain.
Nodes, miners, stakers, wallets, exchanges and other services must move to the emergency release for the recovered network to function consistently. Zano says services are being restored progressively, while users have been advised to verify that third-party services have migrated before sending funds. Reddit
The restart goes considerably further than the roughly 24-hour rollback reportedly considered earlier in the recovery process.
Zano has not yet disclosed the total amount of unauthorized ZANO or fUSD created, the complete technical root cause or final compensation terms. A reimbursement and claims process is expected for affected participants. TokenPost
TOKEN RECON ASSESSMENT
A month-long chain restart is a major intervention because it exchanges transaction finality for monetary integrity.
The vulnerability itself matters, but the recovery decision is the more consequential precedent. Legitimate transactions made during the discarded period now require reconciliation outside the history of the recovered chain.
The next evidence Token Recon needs is the technical postmortem, the amount of unauthorized issuance, and a complete accounting of legitimate activity displaced by the restart. Until those numbers are published, the economic cost of the recovery cannot be measured reliably.
Sources
Zano network recovery statement
TokenPost, Zano restarts blockchain and removes a month of transaction history
