Harmony to Roll Back Blockchain, Erasing 109,000 Transactions After Token Exploit

Layer-1 blockchain Harmony announced plans to roll back its network to August 11, discarding more than 109,000 confirmed transactions following an exploit that resulted in forged ONE tokens being created and distributed. Validators will revert to blocks recorded at 11:25 pm UTC on that date, with new blocks built from that point forward using replacement databases.

Scale of the Rollback

The affected window covers 109,126 regular transactions along with 315 staking transactions. According to the network, restoring only select transactions was not a viable option, since account balances, contract states, transaction nonces, and other chain conditions would no longer match between the original and replacement versions of the ledger.

Investigation Into Forged Tokens

Harmony had been weighing a rollback for over a week after reports surfaced that unauthorized ONE tokens were minted and moved to exchanges. The team said Monday that investigators have now traced nearly all of the forged tokens to specific wallets or service boundaries and are coordinating with exchanges, bridges, and law enforcement to address the fallout. ONE currently holds a market capitalization of roughly $10.8 million.

Not an Isolated Case

Harmony’s decision places it alongside Ravencoin among blockchain networks attempting to reverse already-confirmed activity in the wake of an exploit. Ravencoin recently faced the possibility of a three-day chain reorganization after a flaw in its consensus mechanism was exploited, prompting mining pools controlling most of its hash rate to begin building a competing chain capable of undoing previously confirmed transactions. Ravencoin was trading at $0.002819, giving it a market capitalization of $46.3 million.