Zano restarts chain at block 3,833,000 after Gateway Address exploit erased a month of history

The useful part

Zano has rolled back approximately a month of blockchain history after a vulnerability involving Gateway Addresses allowed unauthorized ZANO and Freedom Dollar to enter circulation, according to its core team. The Zano blockchain has been restarted at block 3,833,000, immediately before Hard Fork 6, which introduced the affected feature. The recovery requires participating nodes, miners, stakers, exchanges and other services to adopt the update, the team said Sunday.

How it works

• The team said it is working to account for any losses and will publish a reimbursement and claims process.
• While it has a native token, ZANO, the blockchain also allows users to deploy and mint custom digital assets.
• Zano's blockchain explorer shows the rollback taking place on Sunday.
• "The total number of unauthorized assets was considerable," Zano's head of marketing and growth Quinten van Welzen told Cointelegraph.

What to take from it

The rollback invalidates a month of legitimate transactions along with the unauthorized tokens, meaning transactions made during that period will no longer appear on the recovered chain. Readers are encouraged to verify information independently. "Doing nothing meant unauthorized ZANO and fUSD in circulation without limit, diluting every holder and breaking the most basic promise a currency makes: a fixed supply," said van Welzen in an X post.

Example or evidence

• "But it restores the supply everyone signed up for, and it leaves a path to rebuild.
• Before Gateway Addresses, Zano's ordinary wallets tracked funds as separate transaction outputs (UTXOs), rather than a single account balance.
• Exchanges and other services had to scan the blockchain to identify incoming payments, track those outputs and select which ones to spend when processing withdrawals.
• Zano Explorer Zano launched in May 2019 as a layer-1 blockchain focused on private payments.

Details worth keeping

It also cannot reverse payments already settled on other blockchains. Its standard private transactions conceal senders, receivers, transferred amounts and asset types. Freedom Dollar (fUSD) is one such token that operates on the Zano blockchain.

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