Ethereum Classic Underwent a Chain Reorg: What Happened?

The news of Ethereum Classic suffering a chain reorg hit the crypto space early Saturday, August 1st. What really happened?

By · Aug 3, 2020 . 7min read

Ethereum classic

The news of Ethereum Classic suffering a chain reorg hit the crypto space early Saturday, August 1st. A total of 3,693 blocks were reorganized. What really happened?

After Binance exchange tweeted the development, CZ replied that he is surprised that the news wasn’t going viral on Twitter.

Binance claimed its risk management system caught the irregularities in the Ethereum Classic network and automatically halted deposits and withdrawals.

While some began claiming the Ethereum Classic chain reorg is another 51% attack on the chain Ethereum Classic Labs developers waded in. In a report, they attempted to explain what happened:

It could be that the offending miner has lost access to internet access for a while when mining, which led to a 12 hour mining period and about 3000 blocks inserted. On the first 2000 blocks, there was 1 miner and a total of 5 transactions. It also seems that the offending miner has uncled their own blocks by how fast they were mining. But it doesn’t appear actively malicious. It might be a deliberate attack as well, but it doesn’t seem there was any major double-spend attack. More investigation of what happened is underway and more information will be released soon.

A definitive statement needed to be out possibly from ETC-Core which are the core development team behind the blockchain network.

Stevan Lohja, the Technology Coordinator at ETC Core, ETC Labs quelled the speculations with an official statement from the team.

Official Report shows the Ethereum Classic Chain Reorg was no 51% Attack

The statement states clearly, the Ethereum Classic chain reorg happened due to an unidentified bug. This bug caused the malfunction of OpenEthereum/Parity and Open-ETC. Subsequently, the bug caused a temporary and minority chain split. Unknowingly to an ETC miner who was mined 3,500 blocks offline, upon returning online, a large chain reorg happened.

Clearly, the official statement on the Ethereum Classic chain reorg rules any possibility of a 51% attack. Interestingly, an attacker successfully carried out a 51% attack on Ethereum Classic in January 2019. About 219,500 ETC were double-spent which was worth about $1.1 million as at then.

However, in this present case, the Ethereum Classic chain reorg hasn’t caused fatal damage to the network as the official report states.

Lohja stated:

The majority chain is operating as normal. The major miners unintentionally mining the incorrect chain are migrating to Core Geth as well as other ETC service providers.

Stevan Lohja’s official statement on the recent Ethereum Classic Chain reorg

Ethereum Classic resulted from the infamous DAO Hack of 2016. With a tethered history, it hasn’t really seen much developers activities. It recently announced its third cohort targetted at Startups last July.