The Ethereum Classic (ETC) blockchain suffered a glitch that scared investors into thinking an attack was underway.
Panic began to spread as reputable members of the crypto community tweeted about a possible 51% attack on the blockchain. A short investigation revealed that it was a glitch which was caused by a miner using an obsolete mining software. The miner tried to create a 3,000 block-insertion nonstop for 12 hours, causing the glitch.
The diagnosis of the event was reported by hackmd.io. According to the report, the miner could have been mining “either offline or [their] total difficulty could have exceeded current network difficulty while they were honestly mining.”
The report also revealed that the block number where the 3,000 block-insertion occurred was 10904146.
From all indications, it appears there was no real attack. It was an honest mistake. Hackmd.io advises miners to “continue mining the chain as-is…This is the recommended option as the chain is following Proof of Work with the longest chain as intended.”
A 51% attack is a known problem associated with blockchains that operate a Proof of Work model. When over 50% of computing power is taken by a miner, transaction verification fails, which could cause transactions to reverse or double-spend.
In January 2019, Coinbase detected a 51% attack and stopped all ETC transactions.
Back in March, Ethereum Classic partnered with Chainlink to incorporate Chainlink data oracles.