SKN | Harmony Plans Rollback, Wiping 109,000 Transactions After ONE Exploit

Key Points:

• Harmony plans to roll back its blockchain to Aug. 11 following an exploit that created forged ONE tokens, discarding 109,126 regular transactions and 315 staking transactions confirmed after the selected checkpoint.
• The network said selectively restoring transactions could create inconsistent balances, contract states and nonces on the replacement chain.
• The rollback places Harmony alongside Ravencoin, which is facing a separate dispute over reorganizing its blockchain after a consensus exploit.

Harmony Sets Aug. 11 Rollback Point

Harmony plans to reverse a portion of its blockchain following an exploit that resulted in the creation of forged ONE tokens.

The layer-1 network said validators will revert the blockchain to blocks recorded at 11:25 pm UTC on Aug. 11. New blocks will then be produced from the following heights using replacement databases.

The rollback will discard more than 109,000 confirmed transactions, marking a significant intervention in the network’s transaction history.

Harmony said the affected period contains 109,126 regular transactions and 315 staking transactions.

The decision follows the network’s consideration of a rollback after reports emerged that unauthorized ONE tokens had been created and transferred to cryptocurrency exchanges.

Selective Restoration Considered Too Risky

Harmony said it considered whether legitimate transactions could be restored selectively rather than discarding the entire affected window.

However, the network concluded that doing so could create inconsistencies across the replacement chain.

Balances, smart-contract states, account nonces and other blockchain conditions could differ between the original and replacement versions, making selective restoration unsafe.

As a result, Harmony opted for a defined rollback point and replacement databases rather than attempting to reconstruct individual transactions.

The approach demonstrates one of the central difficulties associated with blockchain rollbacks: once a large number of transactions have been confirmed, reversing only the activity considered problematic can create additional inconsistencies throughout the network.

Investigators Trace Forged ONE

Harmony said investigators had traced nearly all of the forged ONE tokens to wallets or service boundaries.

The network is working with exchanges, bridges and law enforcement agencies as it continues investigating the incident and attempts to track the affected assets.

The exploit had previously prompted Harmony to work with exchanges to stop or freeze funds associated with the unauthorized token creation.

At the time of the report, ONE had a market capitalization of approximately $10.8 million, according to CoinGecko data.

The incident adds another security challenge for Harmony, which previously suffered the 2022 Horizon Bridge exploit that resulted in approximately $100 million in cryptocurrency being stolen.

Harmony Joins Blockchain Rollback Debate

Harmony’s decision places it alongside Ravencoin, which has faced a separate dispute over whether confirmed blockchain activity should be reversed following an exploit.

Ravencoin experienced a potential three-day blockchain reorganization after a consensus flaw was exploited.

Mining pools controlling most of Ravencoin’s hash rate began constructing a competing chain that could reverse previously confirmed transactions.

The situations are different in their technical details, but both highlight a difficult question for decentralized networks: whether preserving the existing transaction history should take priority when an exploit compromises the integrity of recent activity.

Rollbacks Highlight Blockchain Governance Risks

Blockchain rollbacks are designed to restore a network to a state before problematic activity occurred, but they also introduce questions about transaction finality and network governance.

For users whose legitimate transactions fall within the affected window, the rollback means previously confirmed activity will no longer remain part of the canonical chain.

Harmony’s decision to discard more than 109,000 transactions therefore extends beyond the forged ONE tokens themselves. It affects all network activity occurring after the selected checkpoint, regardless of whether individual transactions were connected to the exploit.

The network’s reliance on replacement databases also illustrates the operational complexity involved in restoring a blockchain after a security incident.

Closing Insights

Harmony’s planned rollback demonstrates the difficult trade-offs blockchain networks face when an exploit compromises recent transaction history. By reverting to Aug. 11, the network intends to remove the affected period rather than selectively reconstruct transactions, but that decision will also erase 109,126 regular transactions and 315 staking transactions from the replacement chain. The incident underscores the tension between maintaining transaction finality and restoring network integrity after a major exploit. As Harmony coordinates with exchanges, bridges and law enforcement to trace the forged ONE tokens, the outcome could provide another important case study in how decentralized networks respond when security failures force them to reconsider already confirmed blockchain activity.