Harmony plans rollback after attack created 3 trillion ONE

Harmony plans to roll its blockchain back to August 11 after an attacker created more than three trillion ONE tokens without authorization.

The rollback would erase the forged coins, but it will come at a cost, because transactions that are legitimate and that were completed after the chosen recovery point would also disappear.

This means exchanges, bridges, and users will have to retrace these transactions that happened during that period.

Harmony chooses rollback despite the disruption

The team wants to return its two affected shards to their state at 23:25:37 UTC on August 11, which is seconds before the first confirmed unauthorized mints.

Harmony reviewed 141,628 blocks from the affected period on Shard 0 alone, and they contained 109,126 regular transactions and another 315 staking transactions. All of these would be erased under the plan, but the team looked at less disruptive alternatives, including destroying selected balances and blocking wallets.

But the unauthorized coins that were produced had already spread into exchanges, bridges, liquidity pools, and wallets containing other users’ funds. If the team tries to remove only the attacker’s coins, it could affect innocent users or leave some forged ones behind.